Update changelog

Author: NoahStapp

doc/changelog.rst

@@ -10,10 +10,10 @@ PyMongo 4.17 brings a number of changes including:
   been deprecated and will be removed in PyMongo 5.0. These methods were
   deprecated in favor of the standard dictionary containment operator ``in``
   and the ``keys()`` and ``values()`` methods, respectively.
-
 - Added the :meth:`~pymongo.asynchronous.client_session.AsyncClientSession.bind` and :meth:`~pymongo.client_session.ClientSession.bind` methods
   that allow users to bind a session to all database operations within the scope of a context manager instead of having to explicitly pass the session to each individual operation.
   See <PLACEHOLDER> for examples and more information.
+- OCSP authentication now uses the more secure SHA-256 hashing algorithm for certificate verification instead of SHA-1.
 
 Changes in Version 4.16.0 (2026/01/07)
 --------------------------------------