Revise changelog for versioning and release date

Updated the changelog to reflect the new versioning format and added release date for version 1.2.3.

Author: thiagogq

CHANGELOG.md

@@ -5,7 +5,9 @@ All notable changes to this project will be documented in this file.
 The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.1.0/),
 and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0.html).
 
-## [1.2.3 - Unreleased] - 2026
+## [Unreleased]
+
+## [1.2.3] - 2026-01-06
 
 ### Fixed