Let Vector 2022 manage its own styles

Depends-On: I9996696795f792567f770ac8bf57002bd5706d06
Bug: T335710
Change-Id: I1f4bddc9091a360795f0ee16f5eed00a7a9ce846

resources/css/ext.uls.pt-vector.less

@@ -1,8 +1,3 @@
-// Resets the background set in jquery.uls for Modern Vector
-.vector-user-links .uls-trigger {
-	background: none;
-}
-
 // Applies old styling rules to legacy Vector
 .skin-vector-legacy {
 	@import 'ext.uls.pt.less';