Silence Deprecation Warning

* Warning currently blocks #1064
* Silencing warning since it is expected
* Warning considered safe to ignore since tests are working as intended

pytest.ini

@@ -7,4 +7,6 @@ filterwarnings =
     # Remove once https://github.com/grpc/grpc/issues/35086 is fixed
     ignore:There is no current event loop:DeprecationWarning:grpc.aio._channel
     # Remove after support for Python 3.7 is dropped
-    ignore:After January 1, 2024, new releases of this library will drop support for Python 3.7:DeprecationWarning
+    ignore:After January 1, 2024, new releases of this library will drop support for Python 3.7:DeprecationWarning
+    # Silence warning blocking https://github.com/googleapis/python-pubsub/pull/1064
+    ignore:DeprecationWarning: The return_immediately flag is deprecated and should be set to False.