Fix failing spec in ee/spec/features/boards/sidebar_spec.rb

If the sidebar Ajax request finishes after loading the Ajax request for
a specific issue, it will clear the assignee, leading to the test
failure. We work around this issue by waiting for the initial request to
be done.

https://gitlab.com/gitlab-org/gitlab/-/issues/216364

ee/spec/features/boards/sidebar_spec.rb

@@ -104,6 +104,8 @@ describe 'Issue Boards', :js do
     it 'assignees to current user' do
       click_card(card2)
 
+      wait_for_requests
+
       page.within(find('.assignee')) do
         expect(find('.qa-assign-yourself')).to have_content('None')