adopt scikit-build-core

[minrk]

• remove setup.py
• requires --no-build-isolation to pip install (previously added by default due to lack of pyproject.toml)

It seems like this might be a nicer way to interact with cmake for Python packages, rather than custom setuptools commands, which seem to be on the way out for compiled code.

Only downside I see is that --no-build-isolation becomes a required arg, so you don't get any benefit from build-system.requires, as those dependencies don't get installed automatically.

I think it could be possible to build without disabling isolation by identifying the parent process to run the ${Python_EXECUTABLE} steps with instead of the default interpreter. I don't know of a robust way to do that, though.

[jorgensd]

Agreed, this looks really nice! Thanks for the effort

[jorgensd]

Superseeded by #91