Update CHANGELOG.md

Author: RobbinBouwmeester

CHANGELOG.md

@@ -6,6 +6,12 @@ The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.0.0/),
 and this project adheres to
 [Semantic Versioning](https://semver.org/spec/v2.0.0.html).
 
+## [3.1.6] - 2025-02-03
+
+### Changed
+
+- Remove unimod, replace with psm_utils
+
 ## [3.1.5] - 2025-02-03
 
 ### Changed