Addresses an issue with how `asyncclick` deals with `KeyboardInterrupt`
errors. Instead of the `click.main` receiving `KeyboardInterrupt` it
receives `CancelledError` because it's a task running inside the loop.
Also ensures that discovery catches the `CancelledError` and closes the
http clients.
Python 3.11 ships with latest Debian Bookworm.
pypy is not that widely used with this library based on statistics. It could be added back when pypy supports python 3.11.
