Installer Action Node16 Deprecation Notice

[IAreKyleW00t]

I noticed that the installer Action is still using Node16 and throws a warning at users since it has been deprecated. Would it be possible to bump this to Node20? Looking at the code, I don't think you're doing anything funky that would be a problem with an upgrade.

Side-note, but somewhat related, I noticed the Action doesn't support other platforms even though slsa-verifier does, and is a bit dated in general. I would be happy to volunteer to give it some love and have things align with some newer standards/practices. 😄