Ensure calls to @close run before the focus-out deactivation

[pichfl]

This wasn't covered by our test suite before.

Expected behavior: Calling @close on a modal will close the modal and in turn should resolve the modal promise with any arguments passed to that function.

Actual behavior: Closing the modal also triggers focus-out, which in turn also calls the modal close callback but without any return data, racing the manual call to @close, which means the modal promise is resolved with undefined because the onDeactivate hook of focus-out runs before the modal close.

This happens because focus-out changed when it's onDeactivate hook is triggered, introducing a new onPostDeactivate which has the same timing as the old one.