SIENTIAPDE-1174

Mark application as DOWN in metrics on shutdown to improve failure reporting

laborious/worker/worker.py

@@ -131,6 +131,7 @@ async def main():
         if activities:
             activities.shutdown()
         # Exit with a non-zero status code to indicate failure to Kubernetes
+        metrics.APP_UP.labels(pod_id=POD_ID).set(0)  # Mark app as DOWN
         sys.exit(1)