fix: fall back to base query when namespace doesn't match any owner

Enterprise system hooks can have path_with_namespace that doesn't match
the Codecov Owner username (e.g. repo owned by an org, not the user in
the path). Try the narrowed query first, fall back to the original.

Made-with: Cursor

Author: thomasrockhu-codecov

apps/codecov-api/webhook_handlers/views/gitlab.py

@@ -91,12 +91,17 @@ def post(self, request, *args, **kwargs):
 
         try:
             if owner:
-                repo = get_object_or_404(
-                    Repository,
+                repo = Repository.objects.filter(
                     author__service=self.service_name,
                     author__username=owner,
                     service_id=project_id,
-                )
+                ).first()
+                if not repo:
+                    repo = get_object_or_404(
+                        Repository,
+                        author__service=self.service_name,
+                        service_id=project_id,
+                    )
             else:
                 repo = get_object_or_404(
                     Repository,