feat: Variadic snippets

packages/svelte/elements.d.ts

@@ -67,7 +67,7 @@ export type MessageEventHandler<T extends EventTarget> = EventHandler<MessageEve
 export interface DOMAttributes<T extends EventTarget> {
 	// Implicit children prop every element has
 	// Add this here so that libraries doing `$props<HTMLButtonAttributes>()` don't need a separate interface
-	children?: import('svelte').Snippet<void>;
+	children?: import('svelte').Snippet;
 
 	// Clipboard Events
 	'on:copy'?: ClipboardEventHandler<T> | undefined | null;

packages/svelte/src/main/public.d.ts

@@ -195,8 +195,8 @@ declare const SnippetReturn: unique symbol;
  * ```
  * You can only call a snippet through the `{@render ...}` tag.
  */
-export interface Snippet<T = void> {
-	(arg: T): typeof SnippetReturn & {
+export interface Snippet<T extends unknown[] = []> {
+	(...args: T): typeof SnippetReturn & {
 		_: 'functions passed to {@render ...} tags must use the `Snippet` type imported from "svelte"';
 	};
 }