Fix DAG formatting (#4023)

dags/bqetl_main_summary.py

@@ -303,7 +303,7 @@ with DAG(
             external_task_id="wait_for_telemetry_derived__clients_last_seen__v1",
             execution_date="{{ (execution_date - macros.timedelta(days=-1, seconds=81000)).isoformat() }}",
         )
-        
+
         ExternalTaskMarker(
             task_id="bqetl_search_dashboard__wait_for_telemetry_derived__clients_last_seen__v1",
             external_dag_id="bqetl_search_dashboard",