PyPI Publish + Semver Actions

[ThomasPluck]

A couple nice to have actions to keep the CI/CD buttery smooth:

• [ ] https://github.com/marketplace/actions/semver-release
• [ ] https://github.com/marketplace/actions/pypi-publish

[dan-fritchman]

Having spent plenty of this morning publishing version 6, I can imagine plenty of improvements.

Just which stuff do these actions do, though?
My brief read of the docs is:

• Publish to PyPi for semver-compatibily tagged (... somethings? PR names?)
• Don't modify any code, markup, etc that has those versions embedded

The reality of the headaches here are really that:

• The "Hdl21 family" is kinda like an unofficial "workspace" including quite a few packages. Mostly python (Hdl21 itself, all the built-in PDKs, VlsirTools, etc), but also the VLSIR bindings to handfuls of other languages.
• That "workspace" is not a formal/ technical thing in Python, or at least any Python tools I know. (Unlike, say, Rust, npm, etc.). And there's certainly no such good multi-language tool that I know, with commands e.g. "bump versions in all".
• So, we keep the same version-string in all of em. They all get published in lock step, whether or not they need to or have changes.
• There's just a lotta finding and replacing that version string? And sometimes missing some instances.
• And then, in Python in particular, there's the painful culture of the runtime __version__ variable, which is an extra pain to keep in sync with the install-time values in setup.py or pyproject.toml. (VLSIR's just failed to update between v2 and v5.)