refactor(users): set mutableUsers in sydnix.users

hosts/sydpc/configuration.nix

@@ -121,17 +121,12 @@
     pkgs.cachix
   ];
 
-  programs.xwayland.enable = true;
-
   services.openssh = {
     enable = true;
     settings.PermitRootLogin = "yes";
     settings.X11Forwarding = true;
   };
 
-  # TODO: Move to defaults.
-  users.mutableUsers = false;
-
   nix = {
     settings = {
       allow-import-from-derivation = true;

modules/nixos/users.nix

@@ -1,18 +1,18 @@
 { config, lib, pkgs, ... }:
 
-with lib;
-
 let
   cfg = config.sydnix.users;
 in {
-  options = {
+  options.sydnix.users = {
-    sydnix.users = {
+    users = lib.mkOption {
-      users = mkOption {
       description =
         "List of usernames whose home profiles should be imported.";
-        type = with types; listOf str;
+      type = with lib.types; listOf str;
       default = [];
     };
   };
+
+  config = {
+    users.mutableUsers = false;
   };
 }