Motivation for this change

As suggested in neovim/neovim#7879 (comment), use Lua instead of LuaJIT for neovim on aarch64. This fixes the neovim build on aarch64; I've successfully built and tested it on a raspberry pi 3.

The neovim cmake file requires the option -DPREFER_LUA=ON if lua is used instead of luajit. This is set of the pname of the lua package is lua.

cc maintainers @garbas @manveru @rvolosatovs

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 nix-review --run "nix-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.