Use new TS option to preserve imports in tests

These assertions were here to prevent imports (needed for svelte-inine-compile) from being removed.

src/lib/components/tabs/TabPanel.svelte

@@ -7,7 +7,8 @@
   import type { SupportedAs } from "$lib/internal/elements";
   import type { HTMLActionArray } from "$lib/hooks/use-actions";
   import Render, { Features } from "$lib/utils/Render.svelte";
-  import { writable, Writable } from "svelte/store";
+  import type { Writable } from "svelte/store";
+  import { writable } from "svelte/store";
   const forwardEvents = forwardEventsBuilder(get_current_component());
 
   export let as: SupportedAs = "div";