[perfalert_inactive_regression] Don't needinfo on bugs with a pending needinfo and don't comment more than once

[suhaibmujahid]

Fixes #2575

@gmierz WDYT?

Checklist

• Type annotations added to new functions
• Docs added to functions touched in main classes
• Dry-run produced the expected results
• The to-be-announced tag added if this is worth announcing

[gmierz]

I'm not okay with that change. We're using those comments/needinfos to keep track of bugs that have no activity happening on them. I'm okay with it not doing a needinfo if there's already a needinfo for the author, as long as the comment is still made and we get it in the bugmail. In the next couple months, we're planning on starting to request backouts for patches that have two consecutive requests for updates with no activity. Just gathering data atm about how often it happens.