Update CHANGELOG.md for version 3.5.3: document fixes for regression in message interoperability and minor remote migration support improvements

Author: grongierisc

CHANGELOG.md

@@ -5,6 +5,12 @@ All notable changes to this project will be documented in this file.
 The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.0.0/),
 and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0.html).
 
+## [3.5.3] - 2025-08-01
+### Fixed
+- Fix a regression test message interoperability where list of messages was not displayed correctly in the UI
+  - This was caused by MessageHandler changes in version 3.5.1
+- Minor fixes for remote migration support
+
 ## [3.5.2] - 2025-08-01
 ### Added
 - Remote migration support, allowing importing Python IOP modules into IRIS through `http`