Update changelog

Author: thecrypticace

CHANGELOG.md

@@ -7,6 +7,10 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 
 ## [Unreleased]
 
+### Fixed
+
+- Don't remove keyframe stops when using important utilities ([#12639](https://github.com/tailwindlabs/tailwindcss/pull/12639))
+
 ### Added
 
 - [Oxide] New Rust template parsing engine ([#10252](https://github.com/tailwindlabs/tailwindcss/pull/10252))