bpo-37658: Fix asyncio.wait_for() to respect waited task status (GH-21894) (GH-21964)

bpo-37658: Fix asyncio.wait_for() to respect waited task status (GH-21894) (GH-21964)

Currently, if `asyncio.wait_for()` itself is cancelled it will always
raise `CancelledError` regardless if the underlying task is still
running.  This is similar to a race with the timeout, which is handled
already.
(cherry picked from commit a2118a14627256197bddcf4fcecad4c264c1e39d)

Co-authored-by: Elvis Pranskevichus <elvis@magic.io>