update changelog

Author: Conduitry

CHANGELOG.md

@@ -3,6 +3,7 @@
 ## Unreleased
 
 * Collapse whitespace in `class` and `style` attributes ([#6004](https://github.com/sveltejs/svelte/issues/6004))
+* Deselect all `<option>`s in a `<select>` where the bound `value` doesn't match any of them ([#6126](https://github.com/sveltejs/svelte/issues/6126))
 * In hydrated components, only rely on helpers for creating the types of elements present in the component ([#6555](https://github.com/sveltejs/svelte/issues/6555))
 * Add `HTMLElement` and `SVGElement` as known globals ([#6643](https://github.com/sveltejs/svelte/issues/6643))
 * Account for scaling in `flip` animations ([#6657](https://github.com/sveltejs/svelte/issues/6657))