Add changelog entry

Author: luke-hill

CHANGELOG.md

@@ -6,6 +6,8 @@ The format is based on [Keep a Changelog](http://keepachangelog.com/)
 and this project adheres to [Semantic Versioning](http://semver.org/).
 
 ## [Unreleased]
+### Changed
+- [Ruby] Minimum supported ruby is now 2.5+
 
 ## [16.1.2] - 2023-01-17
 ### Fixed