Update CHANGELOG.md

Author: driesvints

CHANGELOG.md

@@ -3,6 +3,6 @@
 ## [Unreleased](https://github.com/laravel/framework/compare/v9.0.0...9.x)
 
 
-## [v9.0.0 (2022-??-??)](https://github.com/laravel/framework/compare/v8.80.0...v9.0.0)
+## [v9.0.0 (2022-02-08)](https://github.com/laravel/framework/compare/8.x...v9.0.0)
 
 Check the upgrade guide in the [Official Laravel Upgrade Documentation](https://laravel.com/docs/9.x/upgrade). Also you can see some release notes in the [Official Laravel Release Documentation](https://laravel.com/docs/9.x/releases).