* ✨ Add support for `lifespan` async context managers (superseding `startup` and `shutdown` events). Initial PR [#2944](https://github.com/tiangolo/fastapi/pull/2944) by [@uSpike](https://github.com/uSpike).

Now, instead of using independent `startup` and `shutdown` events, you can define that logic in a single function with `yield` decorated with `@asynccontextmanager` (an async context manager).

For example:

```Python

        lifespan: Annotated[
            Optional[Lifespan[Any]],
            Doc(
                """
                A `Lifespan` context manager handler. This replaces `startup` and
                `shutdown` functions with a single context manager.

                Read more in the
                [FastAPI docs for `lifespan`](https://fastapi.tiangolo.com/advanced/events/).
                """
            ),