fix test

src/components/avatar/avatar.test.ts

@@ -1,4 +1,5 @@
 import { expect, fixture, html } from '@open-wc/testing';
+import { aTimeout } from '@open-wc/testing-helpers';
 
 import '../../../dist/shoelace.js';
 import type SlAvatar from './avatar';
@@ -56,6 +57,9 @@ describe('<sl-avatar>', () => {
     describe('when an error occurs when attempting to load the image', async () => {
       before(async () => {
         el = await fixture<SlAvatar>(html`<sl-avatar image="404.gif" label="${label}"></sl-avatar>`);
+
+        // Wait for the 404 to resolve and trigger an update
+        await el.updateComplete;
       });
 
       it('does not render the "image" part', async () => {