Update CHANGELOG.md

CHANGELOG.md

@@ -5,13 +5,10 @@ All notable changes to Stability Matrix will be documented in this file.
 The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.1.0/),
 and this project adheres to [Semantic Versioning 2.0](https://semver.org/spec/v2.0.0.html).
 
-## v2.6.6
-### Fixed
-- Fixed error when receiving unknown model format values from the Model Browser
-
 ## v2.6.5
 ### Fixed
 - Fixed process errors when installing or updating Pip packages using the Python packages dialog
+- Fixed error when receiving unknown model format values from the Model Browser
 
 ## v2.6.4
 ### Fixed