📝 Update release notes

[skip ci]

Author: github-actions[bot]

docs/en/docs/release-notes.md

@@ -15,6 +15,7 @@ hide:
 
 ### Internal
 
+* ⬆ Bump pymdown-extensions from 10.21.2 to 10.21.3. PR [#15569](https://github.com/fastapi/fastapi/pull/15569) by [@dependabot[bot]](https://github.com/apps/dependabot).
 * ⬆ Bump CodSpeedHQ/action from 4.14.0 to 4.15.1. PR [#15513](https://github.com/fastapi/fastapi/pull/15513) by [@dependabot[bot]](https://github.com/apps/dependabot).
 * ⬆ Bump python-multipart from 0.0.26 to 0.0.29. PR [#15595](https://github.com/fastapi/fastapi/pull/15595) by [@dependabot[bot]](https://github.com/apps/dependabot).
 * 🔒️ Improve GitHub actions security. PR [#15607](https://github.com/fastapi/fastapi/pull/15607) by [@YuriiMotov](https://github.com/YuriiMotov).