Move all project configuration from setup.py to pyproject.toml

[CoolCat467]

In this pull request, I moved all project configuration from setup.py to pyproject.toml.

• Changed the order lines appear in to be identical to Trio's configuration file.
• Added Programming Language :: Python :: 3 :: Only classifier
• Enabled mypy local_partial_types while I'm at it, makes no changes but ensures behaviour is identical to when mypy is running in daemon mode.

Changed continuous integration script to be similar to Trio, adding groups and switching to pyproject based install instead of setup.py script

[CoolCat467]

Having an issue with setup-python:

Version 3.7 was not found in the local cache
Error: The version '3.7' with architecture 'arm64' was not found for macOS 14.4.1.
The list of all available versions can be found here: https://github.com/raw/actions/python-versions/main/versions-manifest.json

[A5rocks]

Either we can drop 3.7 cause it's EOL or we can change macos-latest to macos-13

If we drop 3.7 we can do that in two PRs: remove it from CI here then simplify code/change documentation in another.

[CoolCat467]

Either we can drop 3.7 cause it's EOL or we can change macos-latest to macos-13

If we drop 3.7 we can do that in two PRs: remove it from CI here then simplify code/change documentation in another.

Removed 3.7 from CI

[A5rocks]

Looks good generally, minor feedback. Also it's a bit strange that you added all the towncrier, but I suppose it's there for explicitness/making sure we have the same conventions as trio? Then that's fine by me.

[CoolCat467]

Also it's a bit strange that you added all the towncrier, but I suppose it's there for explicitness/making sure we have the same conventions as trio? Then that's fine by me.

Yes, explicitness and making the same as Trio

[TeamSpen210]

Looks good, only noticed two very minor things.

[A5rocks]

Sorry I forgot this was a thing