nixos/enlightenment: remove some themes and xauth

- E already comes with a default icon theme
- There are already the gtk default Adwaita themes for gtk2, gtk3 and icons
- Remove gnome-icon-theme (from old gtk2)
- Remove tango-icon-theme
- Remove xauth (used by kdesu), as kdesu is not a componnent of E. If
  really needed it should be added in the system configuration.

nixos/modules/services/x11/desktop-managers/enlightenment.nix

@@ -35,11 +35,6 @@ in
     environment.systemPackages = [
       e.efl e.enlightenment
       e.terminology e.econnman
-      pkgs.xorg.xauth # used by kdesu
-      pkgs.gtk2 # To get GTK's themes.
-      pkgs.tango-icon-theme
-
-      pkgs.gnome-icon-theme
       pkgs.xorg.xcursorthemes
     ];