[3.13] gh-109975: Suggest pynntp instead of nntplib (GH-124830) (#124966)

gh-109975: Suggest ``pynntp`` instead of ``nntplib`` (GH-124830)

The ``nntplib`` library has been deleted from PyPI by its author.
(cherry picked from commit ac96482)

Co-authored-by: Christian Clauss <[email protected]>

Author: miss-islington

Doc/whatsnew/3.13.rst

@@ -1559,7 +1559,7 @@ and are now removed:
 * :mod:`!msilib`
 * :mod:`!nis`
 * :mod:`!nntplib`:
-  Use the :pypi:`nntplib` library from PyPI instead.
+  Use the :pypi:`pynntp` library from PyPI instead.
 * :mod:`!ossaudiodev`:
   For audio playback, use the :pypi:`pygame` library from PyPI instead.
 * :mod:`!pipes`: