add release notes

Author: schaubh

docs/source/Support/bskReleaseNotes.rst

@@ -31,6 +31,7 @@ Version |release|
 - Demo video was added to :ref:`scenarioQuadMaps` documentation
 - Pinned python dependencies to avoid issues with new package versions.
 - Added a new github workflow job ``canary`` to routinely check the compatibility of latest python dependencies with python 3.13 on the latest mac-os.
+- Deprecated :ref:`SpacecraftSystem`.  It was never completed and we have other ways to connect spacecraft components
 
 
 Version 2.7.0 (April 20, 2025)