Editor: invalid focusOnMount prop

[mmtr]

Describe the bug
When using the latest package version of the @wordpress/editor npm package the following warning can be observed in the browser console:

Warning: React does not recognize the `focusOnMount` prop on a DOM element. If you intentionally want it to appear in the DOM as a custom attribute, spell it as lowercase `focusonmount` instead. If you accidentally passed it from a parent component, remove it from the DOM element.

It looks like this was introduced in #11401.

To Reproduce
Steps to reproduce the behavior:

• Install latest version of @wordpress/editor package
• Try to build your standalone app with this and render the BlockList component.

[mmtr]

Another way of checking the issue is by running the project locally and opening the editor. After adding a paragraph block and clicking on it for viewing the contextual toolbar, we can inspect the BlockContextualToolbar component in the React devtools.

The focusOnMount prop is propagated down to a div element: