Add to the changelog

Author: antonwolfy

CHANGELOG.md

@@ -4,6 +4,11 @@ All notable changes to this project will be documented in this file.
 The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.1.0/),
 and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0.html).
 
+## [2.6.1] (11/XX/2025)
+
+### Fixed
+* Fixed the run-time dependencies of `mkl-service` package to explicitly depend on a non–free-threaded (GIL-enabled) Python [gh-111](github.com/IntelPython/mkl-service/pull/111)
+
 ## [2.6.0] (10/06/2025)
 
 ### Added