drag_drop_done

Informs GDK that the drop ended.

Passing false for success may trigger a drag cancellation animation.

This function is called by the drag source, and should be the last call before dropping the reference to the this.

The `GdkDrag` will only take the first [method@Gdk.Drag.drop_done] call as effective, if this function is called multiple times, all subsequent calls will be ignored.

Parameters:

this	a `GdkDrag`
success	whether the drag was ultimatively successful