Fix changelog

Author: ksvirkou-hubspot

CHANGELOG.md

@@ -5,7 +5,7 @@ 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).
 
-## [Unreleased](https://github.com/HubSpot/hubspot-api-php/compare/12.1.0...HEAD)
+## [Unreleased](https://github.com/HubSpot/hubspot-api-php/compare/12.2.0...HEAD)
 
 ## [12.2.0](https://github.com/HubSpot/hubspot-api-php/releases/tag/12.2.0) - 2025-04-28