[`flake8-async`] Take `pathlib.Path` into account when analyzing async functions (#9703)
## Summary
This review contains a fix for
[ASYNC101](https://docs.astral.sh/ruff/rules/open-sleep-or-subprocess-in-async-function/)
(open-sleep-or-subprocess-in-async-function)
The problem is that ruff does not take open calls from pathlib.Path into
account in async functions. Path.open() call is still a blocking call.
In addition, PTH123 suggests to use pathlib.Path instead of os.open. So
this might create an additional confusion.
See: https://github.com/astral-sh/ruff/issues/6892
## Test Plan
```bash
cargo test
```