Update CHANGELOG.md

Author: fverdugo

PartitionedSolvers/CHANGELOG.md

@@ -6,11 +6,13 @@ 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).
 
-## [0.2.0] - 2025-07-26
+## [0.2.1] - 2025-07-26
 
 ### Added
 - Support for PartitionedArrays v0.5.
 
+## [0.2.0]
+
 ### Changed
 
 - Linear solver interface.