chore(@mendix/rich-text-web): update changelog

Author: uicontent

Diff for: packages/pluggableWidgets/rich-text-web/CHANGELOG.md

@@ -6,6 +6,8 @@ The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.0.0/),
 
 ## [Unreleased]
 
+## [4.3.1] - 2025-03-19
+
 ### Fixed
 
 -   We fixed minor formatting issues of blank space appearing in between formats.