java: Document breaking change

Author: svix-mman

ChangeLog.md

@@ -1,5 +1,8 @@
 # Changelog
 
+## Version 1.61.1
+* Libs/Java **(Breaking)**: Due to an internal change in the underlining JSON de/serialization library, some JSON objects can no longer be serialized (for example `gson.JsonObject`). To address this `MessageIn.payload` now accepts a JSON encoded string instead of an `Object`
+
 ## Version 1.61.0
 * Libs/Ruby **(Breaking)**: Ruby version changed from `2.7` to `3.4.2`
 * Libs/Ruby **(Breaking)**: Deprecated methods `MessageAttempt.list` and `MessageAttempt.list_attempts_for_endpoint` are removed