use ctp-nix for gtk theme

systems/default.nix

@@ -32,6 +32,7 @@
       ./desktop.nix
       lanzaboote.nixosModules.lanzaboote
       home-manager.nixosModules.home-manager
+      catppuccin.nixosModules.catppuccin
     ]
     ++ nixos;
 in {

systems/desktop.nix

@@ -3,6 +3,7 @@
   pkgs,
   config,
   agenix,
+  catppuccin,
   ...
 }: let
   username = "leo";
@@ -120,6 +121,10 @@ in {
   };
 
   hm = {
+    imports = [
+      catppuccin.homeManagerModules.catppuccin
+    ];
+
     home.packages = with pkgs; let
       inherit (pkgs.stdenv.hostPlatform) system;
     in [
@@ -143,11 +148,6 @@ in {
       sccache
       shotcut
       vesktop
-
-      (catppuccin-gtk.override {
-        variant = "macchiato";
-        accents = ["sky" "sapphire"];
-      })
     ];
 
     services = {
@@ -156,6 +156,15 @@ in {
         pinentryFlavor = "gnome3";
       };
     };
+
+    gtk = {
+      enable = true;
+      catppuccin = {
+        enable = true;
+        flavour = "macchiato";
+        accent = "sky";
+      };
+    };
   };
 
   nixpkgs = {