update changelog

CHANGELOG.md

@@ -5,6 +5,7 @@
 * Allow `<svelte:self>` to be used in a slot ([#2798](https://github.com/sveltejs/svelte/issues/2798))
 * Expose object of unknown props in `$$restProps` ([#2930](https://github.com/sveltejs/svelte/issues/2930))
 * Allow transitions and animations to work within iframes ([#3624](https://github.com/sveltejs/svelte/issues/3624))
+* Fix initialising slot fallbacks when unnecessary ([#3763](https://github.com/sveltejs/svelte/issues/3763))
 * Disallow binding directly to `const` variables ([#4479](https://github.com/sveltejs/svelte/issues/4479))
 * Fix updating keyed `{#each}` blocks with `{:else}` ([#4536](https://github.com/sveltejs/svelte/issues/4536), [#4549](https://github.com/sveltejs/svelte/issues/4549))
 * Fix hydration of top-level content ([#4542](https://github.com/sveltejs/svelte/issues/4542))