Add root users to trusted nix users.

modules/system/settings/nix/default.nix

@@ -13,6 +13,7 @@
         "flakes"
       ];
       auto-optimise-store = true;
+      trusted-users = [ "@wheel" ];
     };
 
     nixpkgs.config.allowUnfreePredicate = pkg: builtins.elem (lib.getName pkg) config.nixpkgs.allowUnfreePackages;