Use hatchling to build the package

[sk1p]

          > Hmm, git revision does not display in the about dialog of the GUI (seen while testing the docker image) - I'll investigate.

_baked_revision.py is present in the wheel, but not in the docker image. I think the proper fix is to use hatchling to build the package, like we are already doing for LiberTEM-{live,blobfinder,...}.