On the post editing page, how do I create a new user and update the Author field

On the post editing page, I add a widget to create a new user and assign them as the author of the post.

My widget calls wp.data.dispatch('core').saveUser({ … }) and creates a new user.

I’m not sure how I can “update” the list of authors in the Author dropdown so that the newly created user is loaded there.

I tried calling
await wp.data.dispatch('core').invalidateResolutionForStore('core')
wp.data.dispatch('core/editor').editPost({author: newUserId})

But this leads to the fact that the new user ID is set BEFORE the list of available users is updated.