[Altair] Adds Thunderbird email, protonmail bridge. [Nix] Fixes deprecated expressions

system/features/gui.nix

@@ -1,11 +1,8 @@
-{ ... }: {
+{ ... }:
+{
   # Enable the X11 windowing system and a display manager
   services.xserver = {
     enable = true;
-    displayManager.gdm = {
-      enable = true;
-      wayland = true;
-    };
     # displayManager.sddm = {
     #   enable = true;
     #   wayland.enable = true;
@@ -17,6 +14,10 @@
       variant = "";
     };
   };
+  services.displayManager.gdm = {
+    enable = true;
+    wayland = true;
+  };
   # services.displayManager.ly.enable = true;
 
   # Enable Hyprland so it shows up in the menu