change Lenni DE to GNOME

modules/nixos/desktop/gnome.nix

@@ -0,0 +1,20 @@
+{ lib, config, ... }:
+lib.mkIf config.desktop.wm.gnome.enable {
+  services = {
+    desktopManager.gnome.enable = true;
+    displayManager.gdm.enable = true;
+  };
+  programs.dconf.profiles.user.databases = [
+    {
+      settings = {
+        "org/gnome/mutter" = {
+          experimental-features = [
+            "scale-monitor-framebuffer" # Enables fractional scaling (125% 150% 175%)
+            "variable-refresh-rate" # Enables Variable Refresh Rate (VRR) on compatible displays
+            "xwayland-native-scaling" # Scales Xwayland applications to look crisp on HiDPI screens
+          ];
+        };
+      };
+    }
+  ];
+}