nixos/gdm: Drop wayland option

daemon/WaylandEnable is gone.

https://gitlab.gnome.org/GNOME/gdm/-/commit/b8fbd8ecc72b2d4974ee91e68407461fe97c5bef

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

@@ -103,6 +103,12 @@ in
       [ "services" "xserver" "displayManager" "gdm" "autoLogin" "delay" ]
       [ "services" "displayManager" "gdm" "autoLogin" "delay" ]
     )
+    (lib.mkRemovedOptionModule [
+      "services"
+      "displayManager"
+      "gdm"
+      "wayland"
+    ] "Disabling this option is no longer supported with GNOME 50.")
   ];
 
   meta = {
@@ -128,14 +134,6 @@ in
         '';
       };
 
-      wayland = lib.mkOption {
-        type = lib.types.bool;
-        default = true;
-        description = ''
-          Allow GDM to run on Wayland instead of Xserver.
-        '';
-      };
-
       autoSuspend = lib.mkOption {
         default = true;
         description = ''
@@ -361,7 +359,6 @@ in
     # presented and there's a little delay.
     services.displayManager.gdm.settings = {
       daemon = lib.mkMerge [
-        { WaylandEnable = cfg.wayland; }
         # nested if else didn't work
         (lib.mkIf (config.services.displayManager.autoLogin.enable && cfg.autoLogin.delay != 0) {
           TimedLoginEnable = true;

nixos/tests/gnome-extensions.nix

@@ -23,10 +23,9 @@
 
       # Configure GDM
       services.xserver.enable = true;
-      services.xserver.displayManager.gdm = {
+      services.displayManager.gdm = {
         enable = true;
         debug = true;
-        wayland = true;
       };
       services.displayManager.autoLogin = {
         enable = true;