update changelog

Author: RobinMalfait

CHANGELOG.md

@@ -19,6 +19,7 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 
 - Discard candidates with an empty data type ([#19172](https://github.com/tailwindlabs/tailwindcss/pull/19172))
 - Fix canonicalization of arbitrary variants with attribute selectors ([#19176](https://github.com/tailwindlabs/tailwindcss/pull/19176))
+- Fix invalid colors due to nested `&` ([#19184](https://github.com/tailwindlabs/tailwindcss/pull/19184))
 
 ## [4.1.15] - 2025-10-20