update change log

Author: DomFijan

ChangeLog.md

@@ -5,7 +5,7 @@ The format is based on [Keep a Changelog] and this project adheres to
 [Keep a ChangeLog]: https://keepachangelog.com/en/1.0.0/
 [Semantic Versioning]: https://semver.org/spec/v2.0.0.html
 
-## 3.X.X -- XXXX-XX-XX
+## 3.4.0 -- 2025-08-05
 
 ### Added
 * Windows wheels on PyPI.