Fix bug where we didn't delete staging push actions

changelog.d/14014.bugfix

@@ -0,0 +1 @@
+Send invite push notifications for invite over federation.

synapse/storage/databases/main/events.py

@@ -2174,7 +2174,7 @@ def _set_push_actions_for_event_and_users_txn(
             (
                 (event.event_id,)
                 for event, _ in all_events_and_contexts
-                if not event.internal_metadata.is_outlier()
+                if event.internal_metadata.is_notifiable()
             ),
         )