nixos/none: remove

This windowManager and desktopManager doesn't even have
an option to use it. git history suggests to me that there's no way anyone
finds this useful anymore.

nixos/modules/module-list.nix

@@ -906,7 +906,6 @@
   ./services/x11/window-managers/icewm.nix
   ./services/x11/window-managers/bspwm.nix
   ./services/x11/window-managers/metacity.nix
-  ./services/x11/window-managers/none.nix
   ./services/x11/window-managers/twm.nix
   ./services/x11/window-managers/windowlab.nix
   ./services/x11/window-managers/wmii.nix

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

@@ -18,7 +18,7 @@ in
   # determines the default: later modules (if enabled) are preferred.
   # E.g., if Plasma 5 is enabled, it supersedes xterm.
   imports = [
-    ./none.nix ./xterm.nix ./xfce.nix ./plasma5.nix ./lumina.nix
+    ./xterm.nix ./xfce.nix ./plasma5.nix ./lumina.nix
     ./lxqt.nix ./enlightenment.nix ./gnome3.nix ./kodi.nix ./maxx.nix
     ./mate.nix ./pantheon.nix ./surf-display.nix ./cde.nix
   ];

nixos/modules/services/x11/desktop-managers/none.nix

@@ -1,7 +0,0 @@
-{
-  services.xserver.desktopManager.session =
-    [ { name = "none";
-        start = "";
-      }
-    ];
-}

nixos/modules/services/x11/window-managers/default.nix

@@ -35,7 +35,7 @@ in
     ./wmii.nix
     ./xmonad.nix
     ./qtile.nix
-    ./none.nix ];
+  ];
 
   options = {
 

nixos/modules/services/x11/window-managers/none.nix

@@ -1,12 +0,0 @@
-{
-  services = {
-    xserver = {
-      windowManager = {
-        session = [{
-          name = "none";
-          start = "";
-        }];
-      };
-    };
-  };
-}