PYTHON-4219 Add changelog entry for 4.6.2 (#1534)

doc/changelog.rst

@@ -66,6 +66,14 @@ Unavoidable breaking changes
     >>> dict_to_SON(data_as_dict)
     SON([('driver', SON([('name', 'PyMongo'), ('version', '4.7.0.dev0')])), ('os', SON([('type', 'Darwin'), ('name', 'Darwin'), ('architecture', 'arm64'), ('version', '14.3')])), ('platform', 'CPython 3.11.6.final.0')])
 
+Changes in Version 4.6.2
+------------------------
+
+PyMongo 4.6.2 fixes the following bug:
+
+- Fixed a bug appearing in Python 3.12 where "RuntimeError: can't create new thread at interpreter shutdown"
+  could be written to stderr when a MongoClient's thread starts as the python interpreter is shutting down.
+
 Changes in Version 4.6.1
 ------------------------