* ♻ Strip empty whitespace from description extracted from docstrings. PR [#2821](https://github.com/tiangolo/fastapi/pull/2821) by [@and-semakin](https://github.com/and-semakin).
* 🐛 Fix cached dependencies when using a dependency in `Security()` and other places (e.g. `Depends()`) with different OAuth2 scopes. PR [#2945](https://github.com/tiangolo/fastapi/pull/2945) by [@laggardkernel](https://github.com/laggardkernel).
* 🐛 Fix `response_model` not invalidating `None`. PR [#2725](https://github.com/tiangolo/fastapi/pull/2725) by [@hukkin](https://github.com/hukkin).
* 🎨 Update type annotations for `response_model`, allow things like `Union[str, None]`. PR [#5294](https://github.com/tiangolo/fastapi/pull/5294) by [@tiangolo](https://github.com/tiangolo).