Update CHANGELOG

Author: ManifoldFR

CHANGELOG.md

@@ -7,7 +7,7 @@ The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.0.0/).
 ## [Unreleased]
 
 ### Added
-- Support for C++11 `std::array` types
+- Support for C++11 `std::array` types ([#412](https://github.com/stack-of-tasks/pull/412))
 
 ## [3.1.4] - 2023-11-27