Wait for all Ajax and Vue requests to complete in JavaScript tests
Wait for all Ajax and Vue requests to complete in JavaScript tests

From logs in #33756, we that it's possible for an Ajax call to be made
before the middleware receives it. To prevent stray Ajax calls from
breaking other specs, we need to wait for all scheduled calls to finish.

Closes #33756

axilleas/gitlabhq,dplarson/gitlabhq,iiet/iiet-git,dreampet/gitlab,dreampet/gitlab,jirutka/gitlabhq,jirutka/gitlabhq,stoplightio/gitlabhq,dreampet/gitlab,dplarson/gitlabhq,stoplightio/gitlabhq,mmkassem/gitlabhq,stoplightio/gitlabhq,mmkassem/gitlabhq,jirutka/gitlabhq,mmkassem/gitlabhq,axilleas/gitlabhq,dplarson/gitlabhq,iiet/iiet-git,t-zuehlsdorff/gitlabhq,axilleas/gitlabhq,jirutka/gitlabhq,dreampet/gitlab,t-zuehlsdorff/gitlabhq,axilleas/gitlabhq,t-zuehlsdorff/gitlabhq,t-zuehlsdorff/gitlabhq,dplarson/gitlabhq,stoplightio/gitlabhq,iiet/iiet-git,mmkassem/gitlabhq,iiet/iiet-git