@asynccontextmanager
async def contextmanager_in_threadpool(
    cm: AbstractContextManager[_T],
) -> AsyncGenerator[_T, None]:
    # blocking __exit__ from running waiting on a free thread
    # can create race conditions/deadlocks if the context manager itself
    # has its own internal pool (e.g. a database connection pool)
    # to avoid this we let __exit__ run without a capacity limit

### Fixes

* 🐛 Allow exit code for dependencies with `yield` to always execute, by removing capacity limiter for them, to e.g. allow closing DB connections without deadlocks. PR [#5122](https://github.com/tiangolo/fastapi/pull/5122) by [@adriangb](https://github.com/adriangb).