update changelog

Author: RobinMalfait

CHANGELOG.md

@@ -21,6 +21,7 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 ### Changed
 
 - Use more modern `--alpha(color / 50%)` syntax instead of `--alpha(color, 50%)` ([#15665](https://github.com/tailwindlabs/tailwindcss/pull/15665))
+- `outline-hidden` and `outline-none` behave the same in non-forced colors mode ([#15690](https://github.com/tailwindlabs/tailwindcss/pull/15690))
 
 ## [4.0.0-beta.9] - 2025-01-09