Deploy without credentials with GitHub Actions and OIDC

I'm in two minds whether this goes into HN or Show HN as it's involved writing a lot of code and exploring an undocumented system. I wouldn't exactly call it reverse engineering as I don't want to attract that kind of attention.

The magic is: federating / trusting GitHub Actions for deploying to various clouds or REST APIs. Hope you enjoy this and it may help you to build an integration for your own project or product.