Switch packaging to pyproject.toml

[ZedThree]

Also requires switching auto-versioning to setuptools_scm from versioneer, as the latter doesn't work with pyproject.toml-only packages

Closes #420

[ZedThree]

Benchmark is failing because the PR is from a fork and so doesn't have push permissions

[ZedThree]

This will also fix the docs not building most of the API: https://easyvvuq.readthedocs.io/en/dev/py-modindex.html

[ZedThree]

This would be pretty trivial to get working with numpy 2.0 as well, the only changes required are:

• replace four instances of np.in1d with np.isin
• loosen the pinned chaospy and numpoly versions

Would you like those changes in this PR or a separate one?

[DavidPCoster]

I'm not an expert on TOML but this looks OK to me

[djgroen]

There's an autopush task failing for some reason. I'll try to rerun the tests.

[djgroen]

Ok, I'm inclined to approve and merge this in and then look into the benchmark build issue if it still exists. Because it's a token error, I suspect this could be a spurious problem?

[djgroen]

Looks generally okay to me. pyproject.toml may need updating, but since the build and tests pass there are no obvious dependency issues at the moment.