📝 Update release notes

docs/en/docs/release-notes.md

@@ -2,6 +2,7 @@
 
 ## Latest Changes
 
+* 🎨 Fix syntax highlighting in docs for OpenAPI Callbacks. PR [#4368](https://github.com/tiangolo/fastapi/pull/4368) by [@xncbf](https://github.com/xncbf).
 * ⬆ Upgrade version pin accepted for Flake8, for internal code, to `flake8 >=3.8.3,<6.0.0`. PR [#4097](https://github.com/tiangolo/fastapi/pull/4097) by [@jamescurtin](https://github.com/jamescurtin).
 * 🐛 Fix support for extending `openapi_extras` with parameter lists. PR [#4267](https://github.com/tiangolo/fastapi/pull/4267) by [@orilevari](https://github.com/orilevari).
 * ✨ Add support for `FrozenSet` in parameters (e.g. query). PR [#2938](https://github.com/tiangolo/fastapi/pull/2938) by [@juntatalor](https://github.com/juntatalor).