Revert "fix(ghostty): add cairo wrapper and make it the default terminal"

This reverts commit 2e58a2d4ad.

modules/system/packages.nix

@@ -1,11 +1,5 @@
 { lib, pkgs, ... }:
 
-let
-  ghosttyCairo = pkgs.writeShellScriptBin "ghostty-cairo" ''
-    export GSK_RENDERER=cairo
-    exec ghostty "$@"
-  '';
-in
 {
   # Baseline system tools available everywhere; users run Home Manager standalone.
   config.environment.systemPackages = lib.mkAfter [
@@ -17,7 +11,6 @@ in
     pkgs.fastfetch
     pkgs.flatpak
     pkgs.ghostty
-    ghosttyCairo
     pkgs.git
     pkgs.home-manager
     pkgs.just