ENH: accept list for labels

[bsipocz]

Currently, we only accept individual labels, it would be convenient to accept a list (e.g. an affects-dev bugfix doesn't require a changelog entry but only if it is done and merged in the same release as its regression pre-cursor, so adding a no-changelog-needed label is not good in case it gets remilestoned/etc.)

[bsipocz]

(I promised to add this, thus assigning for an easier reminder, but anyone please feel free to open a PR if I haven
t done it yet)

[pllim]

Huh... I guess we do check for Affects-dev in the other one:

https://github.com/scientific-python/action-check-changelogfile/blob/ab37ab266b66e8a3e5a0d22c2cf80556716674da/check_changelog.py#L64

I guess I never bothered here because I thought Stuart was gonna fix the Giles bot for astropy all those years ago. 😬

Thanks for tackling this!

[bsipocz]

ahh, thus my surprise as I use Affects-dev all the time in pyvo land :)

[bsipocz]

(But I agree that hard-wiring labels is way too astropy specific, so it should all be doable with the config that the towncrier Action already supports)