Add changelog entry

Signed-off-by: Darshit Chanpura <dchanp@amazon.com>

Author: DarshitChanpura

CHANGELOG.md

@@ -10,6 +10,8 @@ Inspired from [Keep a Changelog](https://keepachangelog.com/en/1.1.0/)
 - Pre-create ML Commons indices for Tenant Aware tests ([#1217](https://github.com/opensearch-project/flow-framework/pull/1217))
 
 ### Infrastructure
+- Onboard to s3 snapshots ([#1252](https://github.com/opensearch-project/flow-framework/pull/1252))
+
 ### Documentation
 ### Maintenance
 ### Refactoring