Use a2wsgi to serve WSGI app

instead of the deprecated starlette WSGIMiddleware that was vendored by
fastAPI. I'm also hoping this fixes the weird exceptions a la:
```
uvicorn.error ERROR 2022-02-14 11:59:42,141 [pN:main,p:4823,tN:Thread-216] Exception in ASGI application
Traceback (most recent call last):
  File "/home/runner/work/galaxy/galaxy/galaxy root/.venv/lib/python3.7/site-packages/uvicorn/protocols/http/h11_impl.py", line 364, in run_asgi
    result = await app(self.scope, self.receive, self.send)
  File "/home/runner/work/galaxy/galaxy/galaxy root/.venv/lib/python3.7/site-packages/uvicorn/middleware/proxy_headers.py", line 75, in __call__
    return await self.app(scope, receive, send)
  File "/home/runner/work/galaxy/galaxy/galaxy root/.venv/lib/python3.7/site-packages/fastapi/applications.py", line 212, in __call__
    await super().__call__(scope, receive, send)
  File "/home/runner/work/galaxy/galaxy/galaxy root/.venv/lib/python3.7/site-packages/starlette/applications.py", line 112, in __call__
    await self.middleware_stack(scope, receive, send)
  File "/home/runner/work/galaxy/galaxy/galaxy root/.venv/lib/python3.7/site-packages/starlette/middleware/errors.py", line 159, in __call__
    await self.app(scope, receive, _send)
  File "/home/runner/work/galaxy/galaxy/galaxy root/.venv/lib/python3.7/site-packages/starlette/exceptions.py", line 71, in __call__
    await self.app(scope, receive, sender)
  File "/home/runner/work/galaxy/galaxy/galaxy root/.venv/lib/python3.7/site-packages/starlette/routing.py", line 656, in __call__
    await route.handle(scope, receive, send)
  File "/home/runner/work/galaxy/galaxy/galaxy root/.venv/lib/python3.7/site-packages/starlette/routing.py", line 408, in handle
    await self.app(scope, receive, send)
  File "/home/runner/work/galaxy/galaxy/galaxy root/.venv/lib/python3.7/site-packages/fastapi/applications.py", line 212, in __call__
    await super().__call__(scope, receive, send)
  File "/home/runner/work/galaxy/galaxy/galaxy root/.venv/lib/python3.7/site-packages/starlette/applications.py", line 112, in __call__
    await self.middleware_stack(scope, receive, send)
  File "/home/runner/work/galaxy/galaxy/galaxy root/.venv/lib/python3.7/site-packages/starlette/middleware/errors.py", line 159, in __call__
    await self.app(scope, receive, _send)
  File "/home/runner/work/galaxy/galaxy/galaxy root/.venv/lib/python3.7/site-packages/starlette_context/middleware/raw_middleware.py", line 96, in __call__
    await self.app(scope, receive, send_wrapper)
  File "/home/runner/work/galaxy/galaxy/galaxy root/.venv/lib/python3.7/site-packages/starlette/middleware/base.py", line 65, in __call__
    task_group.cancel_scope.cancel()
  File "/home/runner/work/galaxy/galaxy/galaxy root/.venv/lib/python3.7/site-packages/anyio/_backends/_asyncio.py", line 574, in __aexit__
    raise exceptions[0]
  File "/home/runner/work/galaxy/galaxy/galaxy root/.venv/lib/python3.7/site-packages/anyio/_backends/_asyncio.py", line 611, in _run_wrapped_task
    await coro
  File "/home/runner/work/galaxy/galaxy/galaxy root/.venv/lib/python3.7/site-packages/starlette/middleware/base.py", line 34, in coro
    await self.app(scope, request.receive, send_stream.send)
  File "/home/runner/work/galaxy/galaxy/galaxy root/.venv/lib/python3.7/site-packages/starlette/exceptions.py", line 71, in __call__
    await self.app(scope, receive, sender)
  File "/home/runner/work/galaxy/galaxy/galaxy root/.venv/lib/python3.7/site-packages/starlette/routing.py", line 656, in __call__
    await route.handle(scope, receive, send)
  File "/home/runner/work/galaxy/galaxy/galaxy root/.venv/lib/python3.7/site-packages/starlette/routing.py", line 408, in handle
    await self.app(scope, receive, send)
  File "/home/runner/work/galaxy/galaxy/galaxy root/.venv/lib/python3.7/site-packages/starlette/middleware/wsgi.py", line 64, in __call__
    await responder(receive, send)
  File "/home/runner/work/galaxy/galaxy/galaxy root/.venv/lib/python3.7/site-packages/starlette/middleware/wsgi.py", line 91, in __call__
    await anyio.to_thread.run_sync(self.wsgi, environ, self.start_response)
  File "/home/runner/work/galaxy/galaxy/galaxy root/.venv/lib/python3.7/site-packages/anyio/_backends/_asyncio.py", line 572, in __aexit__
    raise ExceptionGroup(exceptions)
anyio._backends._asyncio.ExceptionGroup: 2 exceptions were raised in the task group:
----------------------------
Traceback (most recent call last):
  File "/home/runner/work/galaxy/galaxy/galaxy root/.venv/lib/python3.7/site-packages/anyio/_backends/_asyncio.py", line 611, in _run_wrapped_task
    await coro
  File "/home/runner/work/galaxy/galaxy/galaxy root/.venv/lib/python3.7/site-packages/starlette/middleware/wsgi.py", line 98, in sender
    await send(message)
  File "/home/runner/work/galaxy/galaxy/galaxy root/.venv/lib/python3.7/site-packages/starlette/exceptions.py", line 68, in sender
    await send(message)
  File "/home/runner/work/galaxy/galaxy/galaxy root/.venv/lib/python3.7/site-packages/anyio/streams/memory.py", line 193, in send
    self.send_nowait(item)
  File "/home/runner/work/galaxy/galaxy/galaxy root/.venv/lib/python3.7/site-packages/anyio/streams/memory.py", line 177, in send_nowait
    raise BrokenResourceError
anyio.BrokenResourceError
----------------------------
Traceback (most recent call last):
  File "/home/runner/work/galaxy/galaxy/galaxy root/.venv/lib/python3.7/site-packages/starlette/middleware/wsgi.py", line 91, in __call__
    await anyio.to_thread.run_sync(self.wsgi, environ, self.start_response)
  File "/home/runner/work/galaxy/galaxy/galaxy root/.venv/lib/python3.7/site-packages/anyio/to_thread.py", line 29, in run_sync
    limiter=limiter)
  File "/home/runner/work/galaxy/galaxy/galaxy root/.venv/lib/python3.7/site-packages/anyio/_backends/_asyncio.py", line 818, in run_sync_in_worker_thread
    return await future
  File "/home/runner/work/galaxy/galaxy/galaxy root/.venv/lib/python3.7/site-packages/anyio/_backends/_asyncio.py", line 754, in run
    result = context.run(func, *args)
  File "/home/runner/work/galaxy/galaxy/galaxy root/.venv/lib/python3.7/site-packages/starlette/middleware/wsgi.py", line 132, in wsgi
    self.stream_send.send, {"type": "http.response.body", "body": b""}
  File "/home/runner/work/galaxy/galaxy/galaxy root/.venv/lib/python3.7/site-packages/anyio/from_thread.py", line 35, in run
    return asynclib.run_async_from_thread(func, *args)
  File "/home/runner/work/galaxy/galaxy/galaxy root/.venv/lib/python3.7/site-packages/anyio/_backends/_asyncio.py", line 847, in run_async_from_thread
    return f.result()
  File "/opt/hostedtoolcache/Python/3.7.12/x64/lib/python3.7/concurrent/futures/_base.py", line 435, in result
    return self.__get_result()
  File "/opt/hostedtoolcache/Python/3.7.12/x64/lib/python3.7/concurrent/futures/_base.py", line 384, in __get_result
    raise self._exception
  File "/home/runner/work/galaxy/galaxy/galaxy root/.venv/lib/python3.7/site-packages/anyio/streams/memory.py", line 193, in send
    self.send_nowait(item)
  File "/home/runner/work/galaxy/galaxy/galaxy root/.venv/lib/python3.7/site-packages/anyio/streams/memory.py", line 177, in send_nowait
    raise BrokenResourceError
anyio.BrokenResourceError
```

lib/galaxy/dependencies/dev-requirements.txt

@@ -1,5 +1,6 @@
 --extra-index-url https://wheels.galaxyproject.org/simple
 
+a2wsgi==1.4.0; python_version >= "3.6" and python_version < "4.0"
 adal==1.2.7
 aiofiles==0.8.0; python_version >= "3.6" and python_version < "4.0"
 alabaster==0.7.12; python_version >= "3.6" and python_full_version < "3.0.0" or python_full_version >= "3.4.0" and python_version >= "3.6"

lib/galaxy/dependencies/pinned-requirements.txt

@@ -1,5 +1,6 @@
 --extra-index-url https://wheels.galaxyproject.org/simple
 
+a2wsgi==1.4.0; python_version >= "3.6" and python_version < "4.0"
 adal==1.2.7
 aiofiles==0.8.0; python_version >= "3.6" and python_version < "4.0"
 amqp==5.0.9; python_version >= "3.7"

lib/galaxy/webapps/galaxy/fast_app.py

@@ -1,8 +1,8 @@
 from pathlib import Path
 from typing import cast
 
+from a2wsgi import WSGIMiddleware
 from fastapi import FastAPI, Request
-from fastapi.middleware.wsgi import WSGIMiddleware
 from starlette.middleware.cors import CORSMiddleware
 from starlette.responses import (
     FileResponse,

lib/galaxy/webapps/reports/fast_app.py

@@ -1,5 +1,5 @@
+from a2wsgi import WSGIMiddleware
 from fastapi import FastAPI
-from fastapi.middleware.wsgi import WSGIMiddleware
 
 from galaxy.webapps.base.api import (
     add_exception_handler,

lib/tool_shed/webapp/fast_app.py

@@ -1,5 +1,5 @@
+from a2wsgi import WSGIMiddleware
 from fastapi import FastAPI
-from fastapi.middleware.wsgi import WSGIMiddleware
 
 from galaxy.webapps.base.api import (
     add_exception_handler,

packages/webapps/requirements.txt

@@ -1,3 +1,4 @@
+a2wsgi
 galaxy-app
 Cheetah3
 fastapi>=0.68.2,!=0.69.0,!=0.70.0,!=0.70.1

pyproject.toml

@@ -14,6 +14,7 @@ name = "galaxyproject"
 url = "https://wheels.galaxyproject.org/simple"
 
 [tool.poetry.dependencies]
+a2wsgi = "*"
 aiofiles = "*"
 Babel = "*"
 bdbag = "*"

test/unit/webapps/test_send_file.py

@@ -1,8 +1,8 @@
 import tempfile
 
 import pytest
+from a2wsgi import WSGIMiddleware
 from fastapi.applications import FastAPI
-from fastapi.middleware.wsgi import WSGIMiddleware
 from fastapi.testclient import TestClient
 
 from galaxy.util.bunch import Bunch