fix: MenuItemGroup click event propagates

close ant-design/ant-design#29943

Author: afc163

docs/examples/menuItemGroup.tsx

@@ -8,7 +8,7 @@ import '../../assets/index.less';
 export default () => (
   <div>
     <h2>menu item group</h2>
-    <Menu style={{ margin: 20, width: 300 }}>
+    <Menu style={{ margin: 20, width: 300 }} onClick={() => console.log('click')}>
       <MenuItemGroup title="group 1" key="2">
         <MenuItem key="21">2</MenuItem>
         <MenuItem key="22">3</MenuItem>

src/MenuItemGroup.tsx

@@ -38,13 +38,12 @@ class MenuItemGroup extends React.Component<MenuItemGroupProps> {
     const { title, children } = props;
     menuAllProps.forEach((key) => delete props[key]);
 
-    // Set onClick to null, to ignore propagated onClick event
-    delete props.onClick;
     delete props.direction;
 
     return (
       <li
         {...(props as any)}
+        onClick={(e) => e.stopPropagation()}
         className={`${className} ${rootPrefixCls}-item-group`}
       >
         <div