Related #21450

Describe the bug
"Add link..." remains even though one might have changed ones mind in adding a submenu.
To remove it one needs to click into it and add some letters (or click into it and then go to the toolbar select the 3 dots menu and select remove block). Then select the container around it which is hard to see and then click delete on the keyboard.

Steps:

Click menu item. Then click to Add Submenu.

Then change your mind. No submenu is needed anyway.

"Add link..." remains even though one have not added a submenu.

One then needs to either click into the "Add link..." area and then go to the toolbar, click the 3 dots menu and remove block or write some letters into the area then select it and click the delete key on the keyboard.

Solution I would like to see:
The "Add link..." should when not adding a submenu be automatically removed.

Gutenberg 7.8.1
Chrome
Live dev site

(Adding the following info here as well)
William as you worked on the Permalink PR. #12009
When not saving and clicking outside of the box the Permalink would automatically close. I am thinking the same method can be used on this issue and the related adding top level menu item issue I made. #21450
@earnjam