Update CHANGELOG.md

Author: Toni-SM

CHANGELOG.md

@@ -2,7 +2,7 @@
 
 The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.0.0/).
 
-## [1.4.0] - Unreleased
+## [1.4.0] - 2025-01-16
 ### Added
 - Utilities to operate on Gymnasium spaces (`Box`, `Discrete`, `MultiDiscrete`, `Tuple` and `Dict`)
 - `parse_device` static method in ML framework configuration (used in library components to set up the device)