fix: item missing className

Author: zombieJ

src/OptionList/Column.tsx

@@ -78,6 +78,7 @@ export default function Column({
           <li
             key={value}
             className={classNames(menuItemPrefixCls, {
+              [`${menuItemPrefixCls}-expand`]: !isMergedLeaf,
               [`${menuItemPrefixCls}-active`]: openKey === value,
               [`${menuItemPrefixCls}-disabled`]: disabled,
             })}

tests/__snapshots__/index.spec.js.snap

@@ -66,7 +66,7 @@ exports[`Cascader.Basic should render custom dropdown correctly 1`] = `
       class="custom-dropdown"
     >
       <div
-        class="rc-cascader-menu-holder"
+        class="rc-cascader-menus"
       >
         <ul
           class="rc-cascader-menu"

tests/__snapshots__/private.spec.tsx.snap

@@ -50,7 +50,7 @@ exports[`Cascader.Private dropdownPrefixCls 1`] = `
           >
             <li
               aria-checked="false"
-              class="little-menu-item little-menu-item-active"
+              class="little-menu-item little-menu-item-expand little-menu-item-active"
               role="menuitemcheckbox"
               title="Light"
             >