[Releases] Auto-label pull requests on release branches to have "Pick Request"

I looked into whether we can do this via react-native-bot but it seems like the candidates for the bot is based on Github search: https://github.com/hramos/react-native-bot/blob/master/lib/bot/pullrequests.rb#L48

So I think this might need to be a Github action.

Release branches should follow the form: {major}.{minor}-stable

[cortinico]

@lunaleaps would it be fine to use something like github.com/marketplace/actions/label-regex or would it be necessary developing a custom action for this?

My 2 cents here: this can be easily implemented in Danger. We already have a dangerfile here https://github.com/facebook/react-native/blob/main/bots/dangerfile.js with Danger already configured. We would just need to add a rule that checks if base branch != main -> apply the Pick Request label.

[cortinico]

Just a quick follow-up, I was able to test it through my fork of the repo and everything worked great.

Great stuff, thanks for doing it 👍