Move from setup.py to pyproject.toml

[BerndDoser]

pyproject.toml is the new standard for project metadata (PEP 621). Challenging will be the integration of pybind11.

[BerndDoser]

Helpful links

• https://setuptools.pypa.io/en/latest/userguide/pyproject_config.html
• https://setuptools.pypa.io/en/latest/userguide/package_discovery.html
• https://wiki.loliot.net/docs/lang/python/package/pybind11/
• https://github.com/dask/dask/pull/10102