[bug] dragClass having no effect.

[mhabsaoui]

Describe the bug
Using the dragClass to apply a custom backgroud color on dragging list element, but has no effect.

To Reproduce
Steps to reproduce the behavior:

1. Use the react List component from MUI lib
2. Add the ReactSortable component from react-sortablejs and map iterate with list items
3. Add dragClass for custom color

Expected behavior
The custom color should be applied as background color to the dragged element.

Information
react-sortable = ^6.1.4
react = ^18.3.1

Additional context
Some code

 return (
 <List
 component="nav"
 aria-labelledby="institutes"
 subheader={
 <ListSubheader component="h1" id="institutes">
 "selectSource"
 </ListSubheader>
 }>
 <ReactSortable list={sources} setList={setSources} dragClass="dragging">
 {sources.map(({ id, name }) => (
 <ListItemButton
 key={id}
 sx={{
 cursor: "grab",
 }}>
 <ListItemIcon>
 <DragIndicatorIcon />
 </ListItemIcon>
 <ListItemText primary={name} />
 </ListItemButton>
 )}
 </ReactSortable>
 </List>
 );

.dragging{
 background-color: #21ce21;
 color: #fff;
}