Add Github action

[FFY00]

Similar to https://github.com/pypa/gh-action-pypi-publish but to build packages.

[henryiii]

I think this would basically be https://github.com/hynek/build-and-inspect-python-package except without the validation? Edit: also no auto archive uploads.

[FFY00]

Yes, I wasn't aware of that, maybe it doesn't make much sense then though.

[henryiii]

Build uses it. :) It also uses uv and our --installer=uv option, so it's really fast. Not sure we could do better. If we could provide an action that was flexible enough that action could use, though, I think that might be worth while.

(Actually, I use it in so many of my repos that I spent 10 minutes looking for an example of someone learning recently to find one that didn't use it)

[FFY00]

Okay, today I ran into a use-case where that action is a bit undesirable. I want to build a wheel as an intermediary step, and hynek's action always uploads the artifact, which is not needed.