scikit-build-core metadata provider for dynamic versioning

[hannes-holey]

I implemented a version provider for the scikit-build-core build system similar to https://github.com/scikit-build/scikit-build-core/blob/main/src/scikit_build_core/metadata/setuptools_scm.py and in analogy to the already existing meson-python plugin for DiscoverVersion.

Configuration via pyproject.toml:

[tool.scikit-build]
experimental = "true"
metadata.version.provider = "DiscoverVersion.scikit_build_core"