📝 Update release notes

docs/en/docs/release-notes.md

@@ -35,6 +35,7 @@ hide:
 
 ### Internal
 
+* ➕ Add docs dependency: markdown-include-variants. PR [#12399](https://github.com/fastapi/fastapi/pull/12399) by [@tiangolo](https://github.com/tiangolo).
 * 📝 Fix extra mdx-base-path paths. PR [#12397](https://github.com/fastapi/fastapi/pull/12397) by [@tiangolo](https://github.com/tiangolo).
 * 👷 Tweak labeler to not override custom labels. PR [#12398](https://github.com/fastapi/fastapi/pull/12398) by [@tiangolo](https://github.com/tiangolo).
 * 👷 Update worfkow deploy-docs-notify URL. PR [#12392](https://github.com/fastapi/fastapi/pull/12392) by [@tiangolo](https://github.com/tiangolo).