Migrate to pyproject.toml & hatch

[anselor]

The default recommendation from python seems to be hatch now. It has impressive features including declaring build/test configurations and managing venv environments. In my trial of it on a couple small projects I found it to be much faster than using nox to set up venvs.

The problem is it currently doesn't support a monorepo project with multiple modules or plugin modules. There is a development ticket (pypa/hatch#233) that documents it and it is under active development now. Once that is complete we should be able to migrate to hatch with minimal fuss.

[tleonhardt]

I like the idea of moving to something like either hatch or uv and getting rid of nox for running our tests in multiple python environments.

I tried moving to a more modern Python project setup where everything is in pyproject.toml and there are no setup.cfg or setup.py files, but I couldn't get that working properly with nox.

On a semi-related note, I'd also like to replace the mix of flake8, black, and isort for auto-formatting and linting with ruff which is far faster.

[tleonhardt]

#1336 handles the moving to ruff from black, isort, and flake8