SIENTIAPDE-994Add shutdown methods for Activities and OPC classes; enhance worker error handling

laborious/activities/activities.py

@@ -47,3 +47,7 @@ class Activities(Postgres, MLFlow, Gates, OPC):
     @activity.defn(name="prepare_activity")
     async def prepare_activity(self, input_data: dict[str, Any]):
         await super().prepare_activity(input_data)
+
+    def shutdown(self):
+        Postgres.close(self)
+        OPC.shutdown(self)