site: fix rendering of promise in deprecation warning (#9191)

Author: PuruVJ

documentation/docs/02-template-syntax/07-special-elements.md

@@ -200,7 +200,6 @@ If `this` is the name of a [void element](https://developer.mozilla.org/en-US/do
 <script>
 	let tag = 'div';
 
-	/** @type {(e: MouseEvent) => void} */
 	export let handler;
 </script>