chore(custom-chart-web): update changelog

Author: samuelreichert

packages/pluggableWidgets/custom-chart-web/CHANGELOG.md

@@ -6,9 +6,9 @@ The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.0.0/),
 
 ## [Unreleased]
 
-### Changed
+### Fixed
 
-- We updated shared charts dependency.
+- We fixed an issue with incorrect parsing and merging of layout and data properties.
 
 ## [1.2.0] - 2025-06-03