meta: Disable specializations by default

Note that specializations increase the build time and therefore
shouldn't be used unless you're actually using those specializations.
For example, a normal Hyprland build of 30 seconds becomes 1 minute and
30 seconds with the GNOME and Plasma specializations enabled.

As an alternative, you can use multiple nixosConfigurations and only
build GNOME and/or Plsama on demand, then run those desktop environments
as virtual machines inside of Hyprland, which lets you use both (or even
all three) at the same time.

default.nix

@@ -9,6 +9,5 @@
     ./home
     ./modules
     ./overlays
-    ./specializations
   ];
 }