[runx] Proof of concept for runx integration

[mikeland73]

Summary

Inspired by golangci-lint being broken in nixpkgs, I wanted to see if I could get a quick and dirty implementation so we can replace golangci-lint from nixpkgs with runx. The current PR implements this using runx:<path> syntax. Since we already use github:<path> for nix flakes, I can't use that without breaking backwards compatibility. We could overload it.

What this PR implements:

• Add and rm of runx, with and without versions.
• runx installed packages are added to PATH for run, shell, etc

Things that are not implemented by this PR:

• Search and validation. Currently trying to install a non-existing package will fail with a semi-cryptic error.
• lockfile support.

How was it tested?

[savil]

yes, lets do this and start using internally!

Before announcing this to Devbox users:

I have a significant concern about using runx: as the user-facing prefix in devbox.json. I think that'll confuse people: "I'm not running anything". IIRC @mohsenari was confused when you used this term in a meeting.

Finding an alternative would be good. One suggestion is binary:. Good discussion to have with the team and/or users.

[savil]

Would be preferable to include a source reference. In the future, runx may support github, gitlab, sourcehut, custom domain etc.

runx: github.com/golangci/golangci-lint@latest

[mikeland73]

@savil should I merge this with runx or should we decide on the name first?

Another issue I need to fix before merging is the github rate limits on their releases.json endpoint. I need to make changes to runx so that releases.json gets called with github access token.

[savil]

I think we can merge, and make any follow up changes prior to a public announcement. Incremental progress ftw!