SetuptoolsDeprecationWarning: License classifiers are deprecated

[heitbaum]

Warning whilst building

https://packaging.python.org/en/latest/guides/writing-pyproject-toml/#license

Executing (host): python3 -m build -n -w -x 
* Building wheel...
/var/media/DATA/home-rudi/LibreELEC.tv/build.LibreELEC-Generic.x86_64-13.0-devel/toolchain/lib/python3.13/site-packages/setuptools/
dist.py:759: SetuptoolsDeprecationWarning: License classifiers are deprecated.
!!

        ********************************************************************************
        Please consider removing the following classifiers in favor of a SPDX license expression:

        License :: OSI Approved :: MIT License

        See https://packaging.python.org/en/latest/guides/writing-pyproject-toml/#license for details.
        ********************************************************************************

!!
  self._finalize_license_expression()

https://github.com/yaml/pyyaml/blob/69c141adcf805c5ebdc9ba519927642ee5c7f639/setup.py#L26