bundler: fix update

pkgs/by-name/bu/bundler/package.nix

@@ -6,6 +6,7 @@
   testers,
   bundler,
   versionCheckHook,
+  nix-update-script,
 }:
 
 buildRubyGem rec {
@@ -28,20 +29,7 @@ buildRubyGem rec {
   doInstallCheck = true;
 
   passthru = {
-    updateScript = writeScript "gem-update-script" ''
-      #!/usr/bin/env nix-shell
-      #!nix-shell -i bash -p curl common-updater-scripts jq
-
-      set -eu -o pipefail
-
-      latest_version=$(curl -s https://rubygems.org/api/v1/gems/${gemName}.json | jq --raw-output .version)
-      update-source-version ${gemName} "$latest_version"
-    '';
-    tests.version = testers.testVersion {
-      package = bundler;
-      command = "bundler -v";
-      version = version;
-    };
+    updateScript = nix-update-script { };
   };
 
   meta = {