docs: release date

Author: Nelson-numerical-software

CHANGELOG.md

@@ -5,7 +5,7 @@ All notable changes to this project will be documented in this file.
 The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.0.0/),
 and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0.html).
 
-## 1.13.0 - (UNRELEASED)
+## 1.13.0 - (2025-03-29)
 
 This release introduces performance improvements and new graphical capabilities while deprecating support for 32-bit Windows versions.