chore: prepare for version 2.1.1

[skip ci]

Author: ramsey

CHANGELOG.md

@@ -5,6 +5,13 @@ All notable changes to this project will be documented in this file.
 The format is based on [Keep a Changelog](http://keepachangelog.com/en/1.0.0/)
 and this project adheres to [Semantic Versioning](http://semver.org/spec/v2.0.0.html).
 
+## 2.1.1 - 2025-03-23
+
+### Fixed
+
+* Correct the type annotation on `CollectionInterface::column()` to indicate the array
+  it returns is `list<mixed>` ([#130](https://github.com/ramsey/collection/issues/130))
+
 ## 2.1.0 - 2025-03-02
 
 ### Added