ldtk: add passthru.updateScript

pkgs/applications/editors/ldtk/default.nix

@@ -1,5 +1,5 @@
 { lib, stdenv, fetchurl, makeWrapper, makeDesktopItem, copyDesktopItems, unzip
-, appimage-run }:
+, appimage-run, nix-update-script }:
 
 stdenv.mkDerivation rec {
   pname = "ldtk";
@@ -47,6 +47,8 @@ stdenv.mkDerivation rec {
     })
   ];
 
+  passthru.updateScript = nix-update-script { };
+
   meta = with lib; {
     description = "Modern, lightweight and efficient 2D level editor";
     homepage = "https://ldtk.io/";