ci: copy renovate configuration from jms-serializer-uri-handler (#100)

- Update extends from config:base to config:recommended

---------

Co-authored-by: Claude <noreply@anthropic.com>

Author: deviantintegral

renovate.json

@@ -2,7 +2,8 @@
   "$schema": "https://docs.renovatebot.com/renovate-schema.json",
   "extends": [
     "config:recommended",
-    ":preserveSemverRanges"
+    ":preserveSemverRanges",
+    "helpers:pinGitHubActionDigests"
   ],
   "packageRules": [
     {