flake migration (again)

modules/apps/art.nix

@@ -1,10 +1,4 @@
-{ config, lib, pkgs, ... }:
-let
-  unstable = import
-    (builtins.fetchTarball "https://github.com/nixos/nixpkgs/tarball/master") {
-      config = config.nixpkgs.config;
-    };
-in {
+{ config, lib, pkgs, ... }: {
   options.my = {
     apps.art.enable = lib.mkEnableOption "enable";
     dev.gameDev.enable = lib.mkEnableOption "enable";
@@ -22,7 +16,7 @@ in {
         blender # cgi animation and sculpting
       ]) ++ (if config.my.dev.gameDev.enable then [
         godot_4 # game development
-        unstable.gdtoolkit # gdscript language server
+        gdtoolkit # gdscript language server
       ] else
         [ ]);
   };