AP-605: build/publish distribution packages (#9)

* use [`setuptools_scm`](https://setuptools-scm.readthedocs.io/en/latest/) for tracking package versions.
* builds distribution packages published as github artifacts on merge to main.
* builds and publishes packages to pypi on tagging of a new release.
* suppress spurious setuptools_scm warning by explicitly setting a version file
* update changelog to prep for release

reconciling versions (#7)

0.2.0 release (#5)

AP-607: Support Python 3.12 (#2)