GHA release process should be more idempotent

[scottmmjackson]

Had to update some credentials to make the release process work right and the entire workflow failed because a github release already existed.

We should trap for this case and either replace or skip that step.

Not sure if there's anything else we need to do to rerun half-finished releases but it's worth checking it out.

[scottmmjackson]

Looks like we also fail the distributions step when we try to upload an existing package to pypi

[scottmmjackson]

So being a little more clear- once we do the pypi upload there's no backing out. So maybe what we need is:

• [ ] Make PyPI step the last one, and add every other step as a dependency
• [ ] Make github release call idempotent either by trapping for existing release or always deleting and reuploading (the latter feels wrong)