bpo-46469: Make asyncio generic classes return GenericAlias (GH-30777)

* bpo-46469: Make asyncio generic classes return GenericAlias

* 📜🤖 Added by blurb_it.

* Update Misc/NEWS.d/next/Library/2022-01-22-05-05-08.bpo-46469.plUab5.rst

Co-authored-by: Jelle Zijlstra <jelle.zijlstra@gmail.com>

Co-authored-by: blurb-it[bot] <43283697+blurb-it[bot]@users.noreply.github.com>
Co-authored-by: Jelle Zijlstra <jelle.zijlstra@gmail.com>