Add "pmbootstrap check" to run CI scripts locally

fixes #2169 (closed)

Some parts of this code is kind of hacky but it could be a good start and it works.

The original issue said "utilizing Alpine chroots as it makes sense". I should have asked what was meant by this but I moved everything to the chroot so that our tests can be ran on any distro. Consider the case where the distro's pytest is outdated. I think running everything in the chroot makes things reproducible? Maybe Im completely wrong on this =P

I have used "pmbootstrap check" locally and it's convenient to be able to run the CI on my fast machine rather than wait for gitlab.

Hope this helps!