[proposal] github actions automation

[mathematicalmichael]

I would like to propose automating the publishing of packages upon the creation of a github release (not on merge to main).

additionally, automate running tests on PRs - giving confidence to reviewers that things didn't break in an isolated environment.
this is complicated by the need for a GPU - but the CPU testing part can be done.
(I would be willing to volunteer a GPU-equipped machine to host a github actions runner on to perform cuda-based test -- also something I've done before but don't have credentials to do here).

this is a manual process, but a quick one, and the publishing of wheels / source dist to pypi can be done via a secure single-package-scoped access token.

i've done this before a number of times, but I'd need to work with you to handle the secrets management, and first wanted to check if these contributions would be welcome.