📝 Update release notes

[skip ci]

Author: github-actions[bot]

docs/release-notes.md

@@ -13,6 +13,7 @@
 
 ### Internal
 
+* ⬆ Bump pymdown-extensions from 10.21.2 to 10.21.3. PR [#1772](https://github.com/fastapi/typer/pull/1772) by [@dependabot[bot]](https://github.com/apps/dependabot).
 * 📝 Fix categorization of PR 1475 in release notes. PR [#1769](https://github.com/fastapi/typer/pull/1769) by [@svlandeg](https://github.com/svlandeg).
 * ✅ Add Fish shell completion tests for colon options. PR [#1475](https://github.com/fastapi/typer/pull/1475) by [@Mohamed-Elwasila](https://github.com/Mohamed-Elwasila).
 * ✅ Extend completion unit tests for zsh, powershell and pwsh. PR [#1767](https://github.com/fastapi/typer/pull/1767) by [@ADiTyaRaj8969](https://github.com/ADiTyaRaj8969).