update changelog

Author: Conduitry

CHANGELOG.md

@@ -2,6 +2,7 @@
 
 ## Unreleased
 
+* Only apply optimized `src` attribute handling when in an `html` namespace ([#6575](https://github.com/sveltejs/svelte/issues/6575))
 * Fix styles for transitions and animations being attached to the wrong `document` in `<iframe>`s ([#6637](https://github.com/sveltejs/svelte/issues/6637))
 * Fix `<select>` with a `{...spread}` attribute that didn't provide a `value` key getting its value improperly unset ([#6675](https://github.com/sveltejs/svelte/issues/6675))