Building from source (with -v enabled) now yields the following warning:

  !!

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

          License :: OSI Approved :: GNU General Public License v2 (GPLv2)

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

  !!

Which is triggered by

Solution

Simply remove this line:

-license = {text = "GPLv2"} 
+license = "GPL-2.0-only"

Additional Context

The LICENSE file is already automatically copied for both source and binary distributions. So, this change would be purely metadata only.

According to PEP639, a new metadata field can be used to specify what LICENSE files are copied. However, using this new field would require newer versions of pip installed. This new field is really only applicable when multiple licenses are to be included with distributions; previously projects had to manually tell pip what files to copy in case multiple licenses were used. We are only using 1 license for this project.