Update changelog for release 0.21.4

Author: ZzEeKkAa

CHANGELOG.md

@@ -4,6 +4,11 @@ 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).
 
+## [0.21.4] - 2023-10-12
+
+### Fixed
+* Remove dead code to silence Coverity errors. (#1163)
+
 ## [0.21.3] - 2023-09-28
 
 ### Fixed