Remove check for ARIA role

This is testing something built into GOV.UK Frontend, we don’t need to
test it ourselves.

tests/app/main/views/test_broadcast.py

@@ -1970,9 +1970,6 @@ def test_confirm_approve_non_training_broadcasts_errors_if_not_ticked(
     assert normalize_spaces(error_message.text) == (
         'Error: You need to confirm that you understand'
     )
-    assert page.select_one('form.banner input#confirm')['aria-describedby'] == (
-        error_message['id']
-    )
 
     assert mock_update_broadcast_message.called is False
     assert mock_update_broadcast_message_status.called is False