Motivation for this change

was tired of it only supporting pypi

I use the nix eval -f <NIXPKGS_ROOT>/default.nix python3Packages.<package>.src.meta.homepage to determine the owner and repo. NIXPKGS_ROOT is determined from script location, not an environment variable though.

Some limitations:

• If the attr name and directory name differ, it will fail the update
• can't handle "unstable" checkouts due to version logic not being able to handle it ('2018-08-22' vs '1.2.1')?
• If a package is disabled for python3, it will also fail due to the evaluation will throw the " is not supported for python3.8"
  • Maybe this is a plus? a previously python2-only library will probably need some manual work to get working.
• If GITHUB_API_TOKEN (taken from vim plugin conventions) is not given, then user will be limited to 100 api requests; instead of 5000

If an update does fail, the entire update job will still succeed, similar to existing behavior.

Things done

• Tested using sandboxing (nix.useSandbox on NixOS, or option sandbox in nix.conf on non-NixOS linux)
• Built on platform(s)
  • NixOS
  • macOS
  • other Linux distributions
• Tested via one or more NixOS test(s) if existing and applicable for the change (look inside nixos/tests)
• Tested compilation of all pkgs that depend on this change using nix-shell -p nixpkgs-review --run "nixpkgs-review wip"
• Tested execution of all binary files (usually in ./result/bin/)
• Determined the impact on package closure size (by running nix path-info -S before and after)
• Ensured that relevant documentation is up to date
• Fits CONTRIBUTING.md.