Menus: Remove .menu-item-has-children on wp_nav_menu last level menu items when $depth arg is used.
This changeset prevents wp_nav_menu last level menu items from having the .menu-item-has-children class when the $depth argument is used. It adds a loop in wp_nav_menu() to calculate the depth of each menu item with children to make sure the class is added only when applicable.
Props slobodanmanic, kucrut, iCaspar, mdgl, petitphp, audrasjb, costdev.
Fixes #28620.