gradia: add passthru.updateScript

pkgs/by-name/gr/gradia/package.nix

@@ -18,6 +18,7 @@
   webp-pixbuf-loader,
   libsoup_3,
   bash,
+  nix-update-script,
 }:
 python3Packages.buildPythonApplication rec {
   pname = "gradia";
@@ -71,6 +72,8 @@ python3Packages.buildPythonApplication rec {
 
   makeWrapperArgs = [ "\${gappsWrapperArgs[@]}" ];
 
+  passthru.updateScript = nix-update-script { };
+
   meta = {
     description = "Make your screenshots ready for the world";
     homepage = "https://github.com/AlexanderVanhee/Gradia";