fix test fetcher

utils/tests_fetcher.py

@@ -1054,7 +1054,7 @@ def infer_tests_to_run(
         # Then we grab the corresponding test files.
         test_map = create_module_to_test_map(reverse_map=reverse_map, filter_models=filter_models)
         for f in modified_files + impacted_files:
-            if f in test_map:
+            if f in test_map and test_map[f] is not None:
                 test_files_to_run.extend(test_map[f])
         test_files_to_run = sorted(set(test_files_to_run))
         # Remove repo utils tests