Block toolbar positioned under block in the site editor

[tellthemachines]

Description

In the site editor, if the topmost block is longer than the viewport height, the block toolbar is disappearing under the block.

Step-by-step reproduction instructions

1. In a new template, add a Query loop;
2. Make sure the Query has enough content that the block is longer than viewport height;
3. Select Query and see toolbar appearing behind it.

Screenshots, screen recording, code snippet

After Shift+Tab to focus toolbar:

Environment info

No response

Please confirm that you have searched existing issues in the repo.

Yes

Please confirm that you have tested with all plugins deactivated except Gutenberg.

Yes