update changelog

Author: Conduitry

CHANGELOG.md

@@ -8,6 +8,7 @@
 * Fix reactive assignments with destructuring and stores where the destructured value should be undefined ([#4170](https://github.com/sveltejs/svelte/issues/4170))
 * Fix hydrating `{:else}` in `{#each}` ([#4202](https://github.com/sveltejs/svelte/issues/4202))
 * Do not automatically declare variables in reactive declarations when assigning to a member expression ([#4212](https://github.com/sveltejs/svelte/issues/4212))
+* Fix stringifying of attributes in SSR mode when there are spread attributes ([#4240](https://github.com/sveltejs/svelte/issues/4240))
 * Only render one `<title>` in SSR mode when multiple components provide one ([#4250](https://github.com/sveltejs/svelte/pull/4250))
 
 ## 3.16.7