chore: fix change var may cause input type error

web/app/components/workflow/nodes/assigner/components/var-list/index.tsx

@@ -52,6 +52,7 @@ const VarList: FC<Props> = ({
       const newList = produce(list, (draft) => {
         draft[index].variable_selector = value as ValueSelector
         draft[index].operation = WriteMode.overwrite
+        draft[index].input_type = AssignerNodeInputType.variable
         draft[index].value = undefined
       })
       onChange(newList, value as ValueSelector)