go: 1.20.7 -> 1.21.1

[caarlos0]

Description of changes

I noticed that go 1.21 was merged 2 weeks ago, but nixpkgs still install 1.20.

I'm new to Nix, and definitely don't understand the full extend of this change, but its the only place I found that seemed to make sense to reference go 1.21 instead of 1.20.

Judging by the output of nix-build --arg pkgs 'import <nixpkgs> {}' -A go, it seems that is in fact the missing piece.

Anyway, thanks for reviewing, and sorry if I'm out of my mind here :)

Things done

• Built on platform(s)
  • x86_64-linux
  • aarch64-linux
  • x86_64-darwin
  • aarch64-darwin
• For non-Linux: Is sandbox = true set in nix.conf? (See Nix manual)
• Tested, as applicable:
  • NixOS test(s) (look inside nixos/tests)
  • and/or package tests
  • or, for functions and "core" functionality, tests in lib/tests or pkgs/test
  • made sure NixOS tests are linked to the relevant packages
• Tested compilation of all packages that depend on this change using nix-shell -p nixpkgs-review --run "nixpkgs-review rev HEAD". Note: all changes have to be committed, also see nixpkgs-review usage
• Tested basic functionality of all binary files (usually in ./result/bin/)
• 23.11 Release Notes (or backporting 23.05 Release notes)
  • (Package updates) Added a release notes entry if the change is major or breaking
  • (Module updates) Added a release notes entry if the change is significant
  • (Module addition) Added a release notes entry if adding a new NixOS module
• Fits CONTRIBUTING.md.

[zowoq]

This has intentionally not been done yet, it's a reasonable amount of work as need to make sure there isn't much breakage.

I'll do this myself in the next week or two, thanks anyway for the PR.

[caarlos0]

ah, ok, let me know if I can help with anything, go-related or otherwise :)