Update changelog

Author: thecrypticace

CHANGELOG.md

@@ -17,6 +17,7 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 - Ignore consecutive semicolons in the CSS parser ([#18532](https://github.com/tailwindlabs/tailwindcss/pull/18532))
 - Center the dropdown icon added to an input with a paired datalist ([#18511](https://github.com/tailwindlabs/tailwindcss/pull/18511))
 - Extract candidates in Slang templates ([#18565](https://github.com/tailwindlabs/tailwindcss/pull/18565))
+- Improve error messages when encountering invalid functional utility names ([#18568](https://github.com/tailwindlabs/tailwindcss/pull/18568))
 
 ## [4.1.11] - 2025-06-26