Regression: DOM helpers no longer wait on test waiters unless `ember-test-helpers/wait` is imported

I have been attempting to upgrade ember-attacher to ember 3.2 and beyond, but my tests started failing with the new test framework.

Previously, calls on `await click('.stuff')` would wait until all registered test waiters were settled. It appears this is no longer the case. Additionally, merely importing, not using, `ember-test-helpers/wait` (`import wait from 'ember-test-helpers/wait';`) causes tests in that file to pass again. From my sleuthing, importing wait registers the test waiters appropriately.

Thanks!