In PYTHON-4945 we added code to catch and raise CancelledError like this:

        except asyncio.CancelledError:
            raise
        except Exception:
            ...

However I now realize this is redundant. CancelledError inherits from BaseException, not Exception, so we can remove these.

Instead we should only need to audit code that catches BaseException (or bare except). One area we missed is in _client_bulk_shared.py:

    if isinstance(full_result["error"], BaseException):
        raise ClientBulkWriteException(full_result, verbose_results) from full_result["error"]