Add GitHub Actions workflow for Ruby gem release

[parndt]

Closes #3536

This will require us to start tagging with a v prefix

[anitagraham]

Great to see some changes rolling in. I have other changes that I could put together as PRs. Integrating importmap into engines - easy for javascript adding actiontext and activestorage to refinery. Decisions needed about how refinerycms-images works. I have an esbuild step for SCSS, but I'd have to look again to see if it is needed. atb, Anita Anita Graham

[parndt]

@anitagraham PRs sound good; thanks for all the work you put into getting Ruby 4/Rails 8 supported in 03edec5

I'll get this merged so that we can more easily release gem versions again