Relax file source access requirements in tests

By default the user must have the required role and groups. To simplify the setup of other tests, by default `PosixFileSourceSetup` will not require groups unless explicitly specified in the test.
This way we are always testing the default `test user` access through the role.

test/integration/test_remote_files_posix.py

@@ -16,6 +16,15 @@ from galaxy_test.driver.integration_setup import (
 
 
 class PosixFileSourceIntegrationTestCase(PosixFileSourceSetup, integration_util.IntegrationTestCase):
+    @classmethod
+    def handle_galaxy_config_kwds(cls, config):
+        PosixFileSourceSetup.handle_galaxy_config_kwds(
+            config,
+            cls,
+            required_role_expression=REQUIRED_ROLE_EXPRESSION,
+            required_group_expression=REQUIRED_GROUP_EXPRESSION,
+        )
+
     def setUp(self):
         super().setUp()
         self._write_file_fixtures()