(fix) relax instanceof typing

In case no types are known, it will resolve to any instead of unknown

packages/svelte2tsx/svelte-shims.d.ts

@@ -105,7 +105,7 @@ declare function __sveltets_ensureTransition<U extends any[]>(transition: Svelte
 declare function __sveltets_ensureFunction(expression: (e: Event & { detail?: any }) => unknown ): {};
 declare function __sveltets_ensureType<T>(type: AConstructorTypeOf<T>, el: T): {};
 declare function __sveltets_ctorOf<T>(type: T): AConstructorTypeOf<T>;
-declare function __sveltets_instanceOf<T>(type: AConstructorTypeOf<T>): T;
+declare function __sveltets_instanceOf<T = any>(type: AConstructorTypeOf<T>): T;
 declare function __sveltets_allPropsType(): SvelteAllProps
 declare function __sveltets_restPropsType(): SvelteRestProps
 declare function __sveltets_slotsType<Slots, Key extends keyof Slots>(slots: Slots): Record<Key, boolean>;