gradle-completion: add update script

Author: tomodachi94

pkgs/by-name/gr/gradle-completion/package.nix

@@ -3,6 +3,7 @@
   stdenvNoCC,
   fetchFromGitHub,
   installShellFiles,
+  gitUpdater,
 }:
 
 stdenvNoCC.mkDerivation (finalAttrs: {
@@ -38,6 +39,10 @@ stdenvNoCC.mkDerivation (finalAttrs: {
     runHook postInstall
   '';
 
+  passthru.updateScript = gitUpdater {
+    rev-prefix = "v";
+  };
+
   meta = {
     description = "Gradle tab completion for bash and zsh";
     homepage = "https://github.com/gradle/gradle-completion";