📝 Update release notes

[skip ci]

docs/en/docs/release-notes.md

@@ -18,6 +18,7 @@ hide:
 
 ### Refactors
 
+* ♻️ Create `dependency-cache` dict in `solve_dependencies` only if `None` (don't re-create if empty). PR [#13689](https://github.com/fastapi/fastapi/pull/13689) by [@bokshitsky](https://github.com/bokshitsky).
 * ✅ Enable test case for duplicated headers in `test_tutorial/test_header_params/test_tutorial003.py`. PR [#13864](https://github.com/fastapi/fastapi/pull/13864) by [@Amogha-ark](https://github.com/Amogha-ark).
 * 📌 Pin `httpx` to `>=0.23.0,<1.0.0`. PR [#14086](https://github.com/fastapi/fastapi/pull/14086) by [@YuriiMotov](https://github.com/YuriiMotov).