Mention Bot doesn't work with GitHub's CODEOWNERS file

[rallytime]

If you have a CODEOWNERS file in place, as we do here, the action that GitHub assigns in the webhook payload is review_requested instead of opened. Therefore, mention bot skips the PR, even though it is a newly "opened" PR.

While adding review_requested to the check where the PR is skipped if the action != opened is the "easy" work-around, this event is also triggered when reviewers are requested and removed. Obviously, we wouldn't want mention bot commenting each time the review_requested event is triggered.

google/go-github#790

I need to keep looking through the event payload to see if there is a way around this, but I wanted to post here to see if anyone has worked around this before. How can we make mention-bot compatible with GitHub's CODEOWNERS file?

[talarari]

We have a monorepo with CODEOWNERS file and would love to have the bot just read that file and use it instead of fallbackNotifyForPaths.