fix(dropdown-item): remove height property for popup host (#3635)

Author: betavs

src/dropdown-item/dropdown-item.less

@@ -31,7 +31,6 @@
     // 为了解决虚拟节点偶尔出现的问题
     display: block;
     width: 100%;
-    height: max-content;
     overflow: hidden;
     position: absolute;
     left: 0;