Add changelog

Author: philipp-spiess

CHANGELOG.md

@@ -11,6 +11,8 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 
 - Don't rely on `@layer base` for the `@property` polyfills ([#17506](https://github.com/tailwindlabs/tailwindcss/pull/17506))
 - Fix multi-value inset shadow ([#17523](https://github.com/tailwindlabs/tailwindcss/pull/17523))
+- PostCSS: Fix race condition when two changes are queued concurrently ([#17514](https://github.com/tailwindlabs/tailwindcss/pull/17514))
+- PostCSS: Ensure we process files containing an `@tailwind utilities;` directive ([#17514](https://github.com/tailwindlabs/tailwindcss/pull/17514))
 
 ## [4.1.1] - 2025-04-02