Update Change Log

Author: MarkBaker

CHANGELOG.md

@@ -28,6 +28,7 @@ and this project adheres to [Semantic Versioning](https://semver.org).
 ### Fixed
 
 - Xls Reader resolving absolute named ranges to relative ranges [Issue #2826](https://github.com/PHPOffice/PhpSpreadsheet/issues/2826) [PR #2827](https://github.com/PHPOffice/PhpSpreadsheet/pull/2827)
+- Null value handling in the Excel Math/Trig PRODUCT() function [Issue #2833](https://github.com/PHPOffice/PhpSpreadsheet/issues/2833) [PR #2834](https://github.com/PHPOffice/PhpSpreadsheet/pull/2834)
 
 
 ## 1.23.0 - 2022-04-24