fix: ensure element is defined when calling addTabindexIfNoItemsSelected by passing it

This fix should be even much more better than the last one, cause this one will (hopefully) work.

Author: hperrin

packages/list/src/Item.svelte

@@ -66,7 +66,7 @@
 
 <script lang="ts">
   import type { SvelteComponent } from 'svelte';
-  import { onMount, onDestroy, getContext, setContext, tick } from 'svelte';
+  import { onMount, onDestroy, getContext, setContext } from 'svelte';
   import { get_current_component } from 'svelte/internal';
   import type {
     SMUICheckboxInputAccessor,
@@ -179,13 +179,13 @@
   // Reset separator context, because we aren't directly under a list anymore.
   setContext('SMUI:separator:context', undefined);
 
-  onMount(async () => {
+  onMount(() => {
     // Tabindex needs to be '0' if this is the first non-disabled list item, and
     // no other item is selected.
 
     if (!selected && !nonInteractive) {
       let first = true;
-      let el = element;
+      let el = element.getElement();
       while (el.previousSibling) {
         el = el.previousSibling;
         if (
@@ -200,9 +200,8 @@
       if (first) {
         // This is first, so now set up a check that no other items are
         // selected.
-        await tick();
-        addTabindexIfNoItemsSelectedRaf = window.requestAnimationFrame(
-          addTabindexIfNoItemsSelected
+        addTabindexIfNoItemsSelectedRaf = window.requestAnimationFrame(() =>
+          addTabindexIfNoItemsSelected(el)
         );
       }
     }
@@ -336,14 +335,9 @@
     }
   }
 
-  function addTabindexIfNoItemsSelected() {
-    if (!element) {
-      return;
-    }
-
+  function addTabindexIfNoItemsSelected(el: HTMLElement) {
     // Look through next siblings to see if none of them are selected.
     let noneSelected = true;
-    let el = element.getElement();
     while (el.nextElementSibling) {
       el = el.nextElementSibling as HTMLElement;
       if (