update CHANGELOG

Author: matthiasgeihs

packages/keyring-controller/CHANGELOG.md

@@ -7,6 +7,8 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 
 ## [Unreleased]
 
+- KeyringController: add method `exportEncryptionKey`, make salt optional at unlock ([#5984](https://github.com/MetaMask/core/pull/5984))
+
 ## [22.0.2]
 
 ### Fixed