Administration: Fix cursor on first submenu list item in admin menu.

The first submenu item in the collapsed view of the admin menu accepts a click event to navigate, but does not have `cursor: pointer` to indicate that it's interactive. These were removed in [51684], but this specific case (JS activate, menu collapsed, first list item) should remain.

Props mazharulrobeen, sumitsingh, sabernhardt, swapnil1010, joedolson.
Fixes #65250.

git-svn-id: https://develop.svn.wordpress.org/trunk@62568 602fd350-edb4-49c9-b593-d223f7449a82

Author: joedolson

src/wp-admin/css/admin-menu.css

@@ -417,6 +417,10 @@ ul#adminmenu > li.current > a.current:after {
 	border-color: transparent;
 }
 
+.js #adminmenu .wp-submenu .wp-submenu-head {
+	cursor: pointer;
+}
+
 #adminmenu li.current,
 .folded #adminmenu li.wp-menu-open {
 	border: 0 none;