StrEnum 0.5.0

Fix building on Python 3.12+ and modernize packaging.

on Python PyPI

StrEnum couldn't be built from source on Python 3.12 or later, because the vendored copy of versioneer relied on configparser.SafeConfigParser, which no longer exists. This release replaces versioneer with setuptools-scm and moves all the packaging metadata into pyproject.toml. There are no changes to the strenum API.

• Python 3.8 or later is now required. Python 3.7 users will keep getting 0.4.15 from pip.
• The source distribution now includes the tests and their configuration, so packagers can run the test suite. The wheel still contains only the strenum package, its stub files and py.typed.
• pytest-runner is no longer a build requirement.
• The stub files are formatted with black.
• Releases are now built and published to PyPI by GitHub Actions using trusted publishing, and come with provenance attestations.

Fixes #36, #37, #38 and #39.

Full Changelog: v0.4.15...v0.5.0