mergiraf: add updateScript

pkgs/by-name/me/mergiraf/package.nix

@@ -2,6 +2,7 @@
   lib,
   fetchFromGitea,
   rustPlatform,
+  nix-update-script,
 
   # native check inputs
   git,
@@ -30,6 +31,8 @@ rustPlatform.buildRustPackage (finalAttrs: {
 
   versionCheckProgramArg = "--version";
 
+  passthru.updateScript = nix-update-script { };
+
   meta = {
     description = "Syntax-aware git merge driver for a growing collection of programming languages and file formats";
     homepage = "https://mergiraf.org/";