orbeckst
* added support/testing for Python 3.12
* dropped support for Python 2.7 (ye served us well, RIP),
and dropped support for Python 3.7 & 3.8
* internal: switched to pyproject.toml and replaced versioneer with
versioningit: the tags that indicate releases were changed from
release-major.minor.patch to PEP440 compliant major.minor.release