Update CHANGELOG.md sagemaker-core

Author: rsareddy0329

sagemaker-core/CHANGELOG.md

@@ -1,5 +1,12 @@
 # Changelog
 
+## v2.2.0 (2025-12-18)
+
+### Bug Fixes
+* Add xgboost 3.0-5 to release
+* Fix get_child_process_ids parsing issue
+* Fix pip installation issues
+
 ## v2.1.1 (2025-12-10)
 
 ### Bug fixes