* instrumentation/asyncio: catch CancelledError exception in tests
After a29242f49386c097defce500b138dc00f06ce300 we are re-raising the
CancelledError so we need to catch it on the caller side.
Fix#2688
* instrument/asyncio: don't test anext on python < 3.10
Since it's not available there.
* instrumentation/asyncio: use unittest.skipIf instead of reimplementing it
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Co-authored-by: Leighton Chen <lechen@microsoft.com>
