Add missing changelog entry for tailwindlabs#15978

Author: philipp-spiess

CHANGELOG.md

@@ -25,6 +25,7 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 - Find utilities when using the Svelte class shorthand syntax across multiple lines ([#15974](https://github.com/tailwindlabs/tailwindcss/pull/15974))
 - Find utilities when using the Angular class shorthand syntax ([#15974](https://github.com/tailwindlabs/tailwindcss/pull/15974))
 - Find utilities when using functions inside arrays ([#15974](https://github.com/tailwindlabs/tailwindcss/pull/15974))
+- Ensure that `@tailwindcss/browser` does not pollute the global namespace ([#15978](https://github.com/tailwindlabs/tailwindcss/pull/15978))
 - _Upgrade_: Ensure JavaScript config files on different drives are correctly migrated ([#15927](https://github.com/tailwindlabs/tailwindcss/pull/15927))
 
 ## [4.0.0] - 2025-01-21