Use uv's build backend instead of hatch?

[rsyring]

I originally chose hatch as a build backend because it got us away from MANIFEST.IN, it's VCS based file inclusion generally "just worked", and, specifically, let us install from text files generated by pip-compile.

We don't need the text files support anymore and @bchopson let us know that uv's build backend will become the default for uv init as of 0.7.19. We could start using their backend instead of hatch.

I see two issues with that approach:

• Hatch's source distribution build starts with all files in source control. So, in general, there is no need to specify what files are included. uv's build backend basically only takes the python module and everything else must be included.
• Our bump task is dependent on hatch-regex-commit