update changelog

CHANGELOG.md

@@ -4,6 +4,7 @@
 
 * Disallow two-way binding to a variable declared by an `{#await}` block ([#4012](https://github.com/sveltejs/svelte/issues/4012))
 * Allow access to `let:` variables in sibling attributes on slot root ([#4173](https://github.com/sveltejs/svelte/issues/4173))
+* Fix `~=` and class selector matching against values separated by any whitespace characters ([#4242](https://github.com/sveltejs/svelte/issues/4242))
 * Fix code generation for `await`ed expressions that need parentheses ([#4267](https://github.com/sveltejs/svelte/issues/4267))
 * Add some more known globals ([#4276](https://github.com/sveltejs/svelte/pull/4276))
 * Correctly apply event modifiers to `<svelte:body>` events ([#4278](https://github.com/sveltejs/svelte/issues/4278))