LCORE-602: Fix unit-test warning

```
  .../assisted-chat/lightspeed-stack/src/authorization/middleware.py:91: RuntimeWarning: coroutine 'AsyncMockMixin._execute_mock_call' was never awaited
    if not access_resolver.check_access(action, user_roles):
  Enable tracemalloc to get traceback where the object was allocated.
  See https://docs.pytest.org/en/stable/how-to/capture-warnings.html#resource-warnings for more info.
```

`mock_access_resolver` is created as an `AsyncMock`, which makes all its
methods async by default, but `AccessResolver` `check_access` is sync

Author: omertuc

tests/unit/utils/auth_helpers.py

@@ -19,7 +19,7 @@ def mock_authorization_resolvers(mocker: Any) -> None:
         "authorization.middleware.get_authorization_resolvers"
     )
     mock_role_resolver = AsyncMock()
-    mock_access_resolver = AsyncMock()
+    mock_access_resolver = Mock()
     mock_role_resolver.resolve_roles.return_value = set()
     mock_access_resolver.check_access.return_value = True
     # get_actions should be synchronous, not async