refactor(users): set mutableUsers in sydnix.users

modules/nixos/users.nix

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