gossip: set update script

pkgs/by-name/go/gossip/package.nix

@@ -16,6 +16,7 @@
   stdenv,
   wayland,
   wayland-scanner,
+  nix-update-script,
   xorg,
 }:
 
@@ -130,6 +131,8 @@ rustPlatform.buildRustPackage rec {
     })
   ];
 
+  passthru.updateScript = nix-update-script { };
+
   meta = with lib; {
     description = "Desktop client for nostr, an open social media protocol";
     downloadPage = "https://github.com/mikedilger/gossip/releases/tag/${version}";