Update CHANGELOG

Author: stefanzweifel

CHANGELOG.md

@@ -5,10 +5,16 @@ All notable changes to this project will be documented in this file.
 The format is based on [Keep a Changelog](http://keepachangelog.com/en/1.0.0/)
 and this project adheres to [Semantic Versioning](http://semver.org/spec/v2.0.0.html).
 
-## [Unreleased](https://github.com/stefanzweifel/git-auto-commit-action/compare/v4.15.2...HEAD)
+## [Unreleased](https://github.com/stefanzweifel/git-auto-commit-action/compare/v4.15.3...HEAD)
 
 > TBD
 
+## [v4.15.3](https://github.com/stefanzweifel/git-auto-commit-action/compare/v4.15.2...v4.15.3) - 2022-10-26
+
+### Changed
+
+- Use deprecated set-output syntax if GITHUB_OUTPUT environment is not available ([#255](https://github.com/stefanzweifel/git-auto-commit-action/pull/255)) [@stefanzweifel](https://github.com/@stefanzweifel)
+
 ## [v4.15.2](https://github.com/stefanzweifel/git-auto-commit-action/compare/v4.15.1...v4.15.2) - 2022-10-22
 
 ### Changed