Fix CI: Callable import + ControlTaskLike Protocol

Two failures introduced by the previous polish commits caught by CI:

- ruff UP035 on lib/galaxy_test/base/sse.py: Callable must be imported
  from collections.abc, not typing (newer ruff version than the local
  venv had).

- packages mypy on test_sse_dispatch_cache.py:78: the injected
  control_task_factory's type was Callable[[GalaxyQueueWorker],
  ControlTask], which rejected NoopControlTask (and would have also
  rejected FakeControlTask / BoomControlTask) because none of the test
  classes subclass ControlTask.

Introduce a ControlTaskLike Protocol covering the single method the
dispatcher calls (``send_task(**kwargs)``) and type the factory against
it. Keeps ControlTask itself as the production default and lets the
test fakes pass via structural typing.

lib/galaxy/managers/sse_dispatch.py

@@ -15,6 +15,7 @@ from collections.abc import Callable
 from typing import (
     Any,
     Optional,
+    Protocol,
 )
 
 from cachetools import TTLCache
@@ -29,6 +30,17 @@ from galaxy.queues import all_control_queues_for_declare
 from galaxy.web.statsd_client import VanillaGalaxyStatsdClient
 from galaxy.web_stack import ApplicationStack
 
+
+class ControlTaskLike(Protocol):
+    """Structural type for the dispatcher's control-task collaborator.
+
+    The dispatcher only calls ``send_task(**kwargs)``. Typed as a Protocol so
+    tests can pass lightweight fakes (``FakeControlTask``, ``NoopControlTask``)
+    without subclassing ``ControlTask``.
+    """
+
+    def send_task(self, **kwargs: Any) -> Any: ...
+
 log = logging.getLogger(__name__)
 
 
@@ -56,7 +68,7 @@ class SSEEventDispatcher:
         application_stack: ApplicationStack,
         statsd_client: Optional[VanillaGalaxyStatsdClient] = None,
         clock: Callable[[], float] = time.monotonic,
-        control_task_factory: Callable[[GalaxyQueueWorker], ControlTask] = ControlTask,
+        control_task_factory: Callable[[GalaxyQueueWorker], ControlTaskLike] = ControlTask,
         queues_provider: Optional[Callable[[], list[Queue]]] = None,
     ) -> None:
         self._queue_worker = queue_worker

lib/galaxy_test/base/sse.py

@@ -9,10 +9,8 @@ thread instead of silently swallowing them.
 
 import queue
 import threading
-from typing import (
-    Callable,
-    Optional,
-)
+from collections.abc import Callable
+from typing import Optional
 
 import requests