bot to auto add closed-by-bot label when bot close stale issue/PR

[pllim]

Currently, something is not ideal in the cron job setting such that the bot is unable to auto label "closed-by-bot" to stale issue or PR that it closes. A workaround is for the bot to detect a "close" event live (not cron) and auto label those things.

[pllim]

@astrofrog identified for the auto labeling stuff (astropy/astropy-bot#106) that forked repo does not have all the labels in the upstream repo, but I don't think that is a problem for this one, as the label to add is already known, but it is just that the action of setting label does not do anything. So I think it is still some permission problem with cron job.

[pllim]

Attempt started in astropy/astropy-bot#110 . Since it is specific to astropy core, I did not put it here.

[bsipocz]

Hmm, adding a label for auto closure seems to be generically preferable to me, so could it still live in baldrick and being customizable downstream about the specifics of the kind of label it should apply?

[pllim]

AFAIK, the stale scripts only run for astropy core. 🤷‍♀️ I am afraid PR is going to be rejected if I submit this to baldrick.

[bsipocz]

I would support it :)

We advertise baldrick as a generic bot, and this is very much a nice generic functionality even if it's not used yet by many projects.