[3.7] bpo-34490: Fix test_asyncio for AIX - do not call transport.get_extra_info('sockname') (GH-8907) (#9286)

* [3.7] Fix test_asyncio for AIX - do not call transport.get_extra_info('sockname') (GH-8907).
(cherry picked from commit 413118eb)
Co-authored-by: Michael Felt <aixtools@users.noreply.github.com>

* Update test_events.py