update changelog

Author: NoahStapp

doc/changelog.rst

@@ -9,6 +9,14 @@ Version 4.12.1 is a bug fix release.
 - Fixed a bug that could raise ``UnboundLocalError`` when creating asynchronous connections over SSL.
 - Fixed a bug causing SRV hostname validation to fail when resolver and resolved hostnames are identical with three domain levels.
 - Fixed a bug that caused direct use of ``pymongo.uri_parser`` to raise an ``AttributeError``.
+- Fixed a bug where clients created with connect=False and a "mongodb+srv://" connection string
+  could cause public ``pymongo.MongoClient`` and ``pymongo.AsyncMongoClient`` attributes (topology_description,
+  nodes, address, primary, secondaries, arbiters) to incorrectly return a Database, leading to type
+  errors such as: "NotImplementedError: Database objects do not implement truth value testing or bool()".
+- Removed Eventlet testing against Python versions newer than 3.9 since
+  Eventlet is actively being sunset by its maintainers and has compatibility issues with PyMongo's dnspython dependency.
+- Fixed a bug where MongoDB cluster topology changes could cause asynchronous operations to take much longer to complete
+  due to holding the Topology lock while closing stale connections.
 
 Issues Resolved
 ...............