[3.12] gh-96747: Mention the PyPI passlib package in the crypt deprecation doc (GH-106660) (#106660)

* Added mention to passlib package as alternative to the deprecated crypt module.

Author: bityob

Doc/library/crypt.rst

@@ -20,6 +20,7 @@
    The :mod:`crypt` module is deprecated
    (see :pep:`PEP 594 <594#crypt>` for details and alternatives).
    The :mod:`hashlib` module is a potential replacement for certain use cases.
+   The `passlib <https://pypi.org/project/passlib/>`_ package can replace all use cases of this module.
 
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