bpo-39674: Revert "bpo-25988: Do not expose abstract collection classes in the collections module. (GH-10596)" by vstinner · Pull Request #18545 · python/cpython

The deprecation originally slated for 3.9 was deferred to 3.10
(bpo-39674, pythonGH-18545) and the documentation on the 3.8 release was
updated accordingly (pythonGH-18748). However the deprecation notice in
the code was left as is, and still indicates deprecation with 3.9.

The deprecation originally slated for 3.9 was deferred to 3.10
(bpo-39674, pythonGH-18545). However the deprecation notice in the release
was left as is, and still indicates deprecation with 3.9.

Also add a missing space in the message.

The deprecation originally slated for 3.9 was deferred to 3.10
(bpo-39674, GH-18545) and the documentation on the 3.8 release was
updated accordingly (GH-18748). However the deprecation notice in
the code was left as is, and still indicates deprecation with 3.9.