Don't tag owners in the bot "ready to merge" comment

After approving any DT PR, I unsubscribe myself so that I don't get any notifications about it. I've given my stamp and my work is done in my opinion.

Unfortunately some indeterminate time later, I always get @ tagged by the bot "helpfully" letting me know that I can merge the PR on behalf of the author by commenting.

It's frustrating because

1. I cannot unsubscribe from the notification - I'm forced to get the ping.
   An @ tag also pushes a notification to my phone via the GH app, interrupting me (the app provides no filters here - just "on" or "off" for direct mentions).
   Additionally the @ tag resubscribes me to the thread.
2. It's a super low value thing to @ tag me for. It's the N+1th time seeing the comment - I know this feature exists. I really don't want to be directly told about it again.
   Additionally (IMO) it's not my duty to merge someone else's PR, so personally I'm not ever going to take this action.

I would like to see the @ tagging of owners removed from this follow up comment to reduce notification noise for owners.
The comment obviously still has a lot of value! Just the @ tagging of owners should be removed so that owners can unsubscribe if they wish.

Start by locating the bot entry point that generates the “ready to merge” follow-up comment. Confirm how owner mentions are added, then verify the comment still explains that the pull request can be merged without tagging owners.