fix: Add shipping method data validation (#9542)

* fix: Add shipping method data validation

* fix: return type

packages/medusa/src/api/store/carts/[id]/shipping-methods/route.ts

@@ -1,17 +1,16 @@
-import { addShippingMethodToWorkflow } from "@medusajs/core-flows"
+import { addShippingMethodToCartWorkflow } from "@medusajs/core-flows"
 import { MedusaRequest, MedusaResponse } from "@medusajs/framework/http"
+import { HttpTypes } from "@medusajs/framework/types"
 import { refetchCart } from "../../helpers"
 import { StoreAddCartShippingMethodsType } from "../../validators"
-import { HttpTypes } from "@medusajs/framework/types"
 
 export const POST = async (
   req: MedusaRequest<StoreAddCartShippingMethodsType>,
   res: MedusaResponse<HttpTypes.StoreCartResponse>
 ) => {
-  const workflow = addShippingMethodToWorkflow(req.scope)
   const payload = req.validatedBody
 
-  await workflow.run({
+  await addShippingMethodToCartWorkflow(req.scope).run({
     input: {
       options: [{ id: payload.option_id, data: payload.data }],
       cart_id: req.params.id,