fix: Handled the cases where during column dnd and mouse goes out and in of viewport

packages/nc-gui/components/smartsheet/grid/useColumnDrag.ts

@@ -49,6 +49,8 @@ export const useColumnDrag = ({
 
   const onDrag = (e: DragEvent) => {
     if (!e.dataTransfer) return
+    if (!draggedCol.value) return
+
     e.preventDefault()
 
     if (!dragColPlaceholderDomRef.value) return