OZG-4528 fix test

alfa-client/libs/vorgang-detail/src/lib/vorgang-detail-page/vorgang-detail-area/vorgang-detail-antragsteller/vorgang-detail-antragsteller.component.spec.ts

@@ -251,7 +251,7 @@ describe('VorgangDetailAntragstellerComponent', () => {
     it('should be visible', () => {
       const element = getElementFromFixture(fixture, antragstellerAdresse);
 
-      expect(element).toHaveClass('mdc-list-item');
+      expect(element).toBeInstanceOf(HTMLElement);
     });
 
     it('should not be visible', () => {