chore(@mendix/combobox-web): update changelog

Author: uicontent

packages/pluggableWidgets/combobox-web/CHANGELOG.md

@@ -6,6 +6,8 @@ The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.0.0/),
 
 ## [Unreleased]
 
+## [2.8.0] - 2026-03-09
+
 ### Added
 
 - We introduced a new "On change" action in Database mode that fires only when the selection changes, unlike the previous behavior that fired on initialization.