update release notes

Author: Natsoulas

docs/source/Support/bskReleaseNotes.rst

@@ -103,6 +103,8 @@ Version  |release|
 
 - Update CI Linux build with ``opNav`` to use Ubuntu 22.04, not latest (i.e. 24.02).  The latter does not
   support directly Python 3.11, and Basilisk does not support Python 3.13 yet.
+- Added a fix for the message subscription bug in which the message data was not retained after going out of scope.
+- Added unit test for message subscription and message data retention after going out of scope to ``test_messaging.py``.
 
 
 Version 2.5.0 (Sept. 30, 2024)