Switch from setuptools to hatch

[TimMonko]

References and relevant issues

I dunno, hatch is simpler and newer - seems first classed in a lot of tutorial materials.

Description

1. Switch pyproject to use hatch. By default, the extra setuptools stuff we had is accounted for by hatch
2. Switch gh action to hatch
3. oh I guess we get to remove MANIFEST.in so that's a victory!

For example, here is a new project of mine... importantly it ships napari.yaml in the wheel
I have tests in root on this project, so I'd assume they'd get stuck in the wheel unless we do #83
Anyways, I'm happy with this but don't know if I'm missing something (as I said, it works in a new project of mine, see ndev-kit/ndevio#4

c:\Users\timmo\ndevio>cd c:\Users\timmo\ndevio && python -m zipfile -l "dist\ndevio-0.1.dev6+gc946c61.d20250801-py3-none-any.whl"
File Name                                             Modified             Size
ndevio/__init__.py                             2020-02-02 00:00:00          526
ndevio/_reader.py                              2020-02-02 00:00:00         2502
ndevio/_widget.py                              2020-02-02 00:00:00         4811
ndevio/_writer.py                              2020-02-02 00:00:00         1958
ndevio/napari.yaml                             2020-02-02 00:00:00         1818
ndevio-0.1.dev6+gc946c61.d20250801.dist-info/METADATA 2020-02-02 00:00:00         6286
ndevio-0.1.dev6+gc946c61.d20250801.dist-info/WHEEL 2020-02-02 00:00:00           87
ndevio-0.1.dev6+gc946c61.d20250801.dist-info/entry_points.txt 2020-02-02 00:00:00           46
ndevio-0.1.dev6+gc946c61.d20250801.dist-info/licenses/LICENSE 2020-02-02 00:00:00         1484
ndevio-0.1.dev6+gc946c61.d20250801.dist-info/RECORD 2020-02-02 00:00:00          874