[PostgresClient]: PostgresClient should abort trying to connect on graceful shutdown

### Please summarize your feature request PostgresClient should stop attempts at connecting when the service is already shutting down ### Describe the functionality you're seeking in more detail When PostgresClient tries to run a query, and it tries to connect to the db, it might fail because of connection issues. It will then time out on the connection, and try again. Currently it will potentially endlessly retry and the server cannot be shut down. If a user then tries to shut down the server, PostgresClient should stop any attempts. Currently (I am using Hummingbird) you have to kill the process to get out of this and stop the server. ### Have you considered any alternatives? _No response_