Logging may leak slack webhook secret

The current:
except Exception as slack_exc:
logger.error(f"Failed to post Slack alert: {slack_exc}")

may leak slack webhook secret in the case of an unhandled application exception that triggers notify_slack_of_exception() because we currently send slack alert through our app and whether this slack notification is successful or not, urllib3's debug request log (if successful) or the full slack_exc info (if failed) may be in log.

Reproduce this if you plan to fix this.

Locate notify_slack_of_exception() and the shown logger.error handler, then reproduce the Slack alert path as the issue requests. Inspect urllib3 debug output and slack_exc logging for both successful and failed notifications; done means the Slack webhook secret is not exposed in application or request logs.

Written by the indexing model from the issue text.