This makes using specific versions of zig easier (without overrides)
Also, a cosmetic refactor: - Reorder parameter listing - Use rec-less, overlay-style overridable recursive attributes (in effect since NixOS#119942); - Remove nested with (according to https://nix.dev/recipes/best-practices#with-scopes)
Closes https://github.com/NixOS/nixpkgs/pull/209537
When using, ensure to install a waylock pam.d file. On NixOS use `security.pam.services.waylock = {}`.