nixos/gdm: Remove stray with pkgs.gnome;

It was unused – `gdm` is part of the outer scope.

Author: jtojnar

nixos/modules/services/x11/display-managers/gdm.nix

@@ -206,7 +206,7 @@ in
       ];
 
     # Otherwise GDM will not be able to start correctly and display Wayland sessions
-    systemd.packages = with pkgs.gnome; [
+    systemd.packages = [
       gdm
       pkgs.gnome-session
       pkgs.gnome-shell