Update changelog

Author: adamwathan

CHANGELOG.md

@@ -34,6 +34,7 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 - Remove fixed line-height theme values and derive `leading-*` utilites from `--spacing-*` scale ([#14857](https://github.com/tailwindlabs/tailwindcss/pull/14857))
 - Remove `--transition-timing-function-linear` from the default theme in favor of a static `ease-linear` utility ([#14880](https://github.com/tailwindlabs/tailwindcss/pull/14880))
 - Remove default `--spacing-*` scale in favor of `--spacing` multiplier ([#14857](https://github.com/tailwindlabs/tailwindcss/pull/14857))
+- Remove `var(…)` fallbacks from theme values in utilities ([#14881](https://github.com/tailwindlabs/tailwindcss/pull/14881))
 
 ## [4.0.0-alpha.31] - 2024-10-29