Product security doesn't receive an email when the PSIRT issue is closed

### Describe the bug

When the PSIRT issue is closed, it will no longer receive replies.

### Version

main

### Expected behavior

The bot should start a new thread with PSIRT automatically

### Actual behavior

The message is lost

### How to Reproduce?

_No response_

### Anything else?

Product security mentioned they would have an autoresponder up and running eventually. Let's follow up on that.

No file, test, or entry point is named in the issue. Start by locating the bot flow that handles closed PSIRT issues and review how it communicates with the external PSIRT autoresponder. Done means a closed PSIRT issue reliably starts a new thread instead of losing the message, with the dependency and expected behavior confirmed.

Written by the indexing model from the issue text.