[nix] Add package for official golang binaries

[maru-ava]

Why this should be merged

Ensures the availability of the required golang version in the nix dev shell.

How this works

• Adds a nix derivation for the go package in nix/go.nix
• Adds the package to the dev shell

How this was tested

Locally verified to work. Attempts to use in CI are not recommended since it doesn't support dependency caching like action/setup-go.

Need to be documented in RELEASES.md?

N/A

[JuanLeon2]

Can you expand why this is not risky: "Attempts to use in CI are not recommended since it doesn't support dependency caching like action/setup-go." What if someone tries to use it in CI?

[JuanLeon2]

Actually, this seems to have been superseded by PR 3826 #3826

True?

Can you remove this PR in that case?

[StephenButtolph]

@JuanLeon2 I don't think this PR has been superseded. #3826 seems to depend on this PR, not supersede it.

[maru-ava]

Can you expand why this is not risky: "Attempts to use in CI are not recommended since it doesn't support dependency caching like action/setup-go." What if someone tries to use it in CI?

setup-go is an action provided by github, that automatically caches golang module dependencies on a per-job basis. So the first job run will cache things, and subsequent runs can use the cache (unless their are go.mod changes that require re-caching).

This PR ensures that golang is available in the nix shell mainly to ensure a consistent development environment, and though the potential exists to just use nix for everything in CI, that would likely require enabling similar support for caching as setup-go already supports. I figure that work is probably unjustified at least for now.

So, not really a risk. A given job would just run a bit slower without the module cache provided by setup-go.

[maru-ava]

I'm going to mark this PR as draft for now, I realize it's probably desirable to provide a CI shell distinct from the current development shell to ensure that setup-go is the only source of golang in CI.