Update date in release notes

Author: martignoni

CHANGELOG.md

@@ -3,7 +3,7 @@
 All notable changes to this project will be documented in this file.
 This project adheres to [Semantic Versioning](https://semver.org/) and follow principles of [keep a changelog](https://keepachangelog.com).
 
-## Version 2.18.2, unreleased
+## Version 2.18.2, 2024-10-31
 
 __This version is not compatible with versions of Moodle prior to Moodle 4.4!__