Feature request: add labels to automatic PRs

[MayeulC]

Hello, I maintain the Flathub package for Unciv, and the frequency of upstream releases is astonishingly high, which leads to a lot of PRs. For filtering purposes, would it be possible to make the bot label the issues?

(and ideally, auto-close stale obsolete PRs, but this is rare enough that I can do it by hand).