Update CHANGELOG.md

Author: barryvdh

CHANGELOG.md

@@ -5,6 +5,12 @@ 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).
 
+## 1.2.0 (Unreleased)
+
+### Changed
+ - Drop support for PHP 7.2/7.3 and legacy Symfony HttpFoundation versions.
+ - Used TypedProperties instead of manual validation
+ 
 ## 1.1.0 (2022-02-20)
 
 ### Added