Update test/relative-time.js

Co-authored-by: Copilot <175728472+Copilot@users.noreply.github.com>

Author: khiga8

test/relative-time.js

@@ -1893,7 +1893,7 @@ suite('relative-time', function () {
       await Promise.resolve()
 
       assert.isNull(time.querySelector('[aria-hidden]'), 'Expected no aria-hidden to be present')
-      assert.isNull(time.querySelector('span'), 'Expected no span to be present')
+      assert.isNull(time.shadowRoot.querySelector('span'), 'Expected no span to be present')
     })
 
     test('no aria-hidden applies to shadow root', async () => {