xfce.catfish: Fix double wrapping resulting in wrong StartupWMClass

pkgs/desktops/xfce/applications/catfish/default.nix

···
   # Disable check because there is no test in the source distribution
   doCheck = false;
 
+  dontWrapGApps = true;
+
+  preFixup = ''
+    makeWrapperArgs+=("''${gappsWrapperArgs[@]}")
+  '';
+
   passthru.updateScript = gitUpdater { rev-prefix = "${pname}-"; };
 
   meta = with lib; {