Motivation for this change

Cleaned up the expression a bit.

As for the docgen requires, lua docs state:

To determine its path, require first checks the global variable LUA_PATH. If the value of LUA_PATH is a string, that string is the path. Otherwise, require checks the environment variable LUA_PATH. Finally, if both checks fail, require uses a fixed path (typically "?;?.lua", although it is easy to change that when you compile Lua).

Not sure why it does not work.

cc @lprndn @emmanuelrosa
cc @teto (#55747)

Things done

• Tested using sandboxing (nix.useSandbox on NixOS, or option sandbox in nix.conf on non-NixOS)
• 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 nox --run "nox-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)
• Assured whether relevant documentation is up to date
• Fits CONTRIBUTING.md.