docs: add changelog entry

Author: DannyvdSluijs

CHANGELOG.md

@@ -21,6 +21,7 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 ### Changed
 - Used PHPStan's int-mask-of<T> type where applicable ([#779](https://github.com/jsonrainbow/json-schema/pull/779))
 - Fixed some PHPStan errors ([#781](https://github.com/jsonrainbow/json-schema/pull/781))
+- Cleanup redundant checks ([#796](https://github.com/jsonrainbow/json-schema/pull/796))
 
 ## [6.1.0] - 2025-02-04
 ### Added