fix: adjustments based on seb's feedback

- remove eager from shipping_option relationship in `models/custom-shipping-options.ts`
- remove custom_shipping_options relation from cart model

packages/medusa/src/api/routes/store/shipping-options/__tests__/list-shipping-options.js

@@ -29,7 +29,6 @@ describe("GET /store/shipping-options", () => {
             "items",
             "items.variant",
             "items.variant.product",
-            "custom_shipping_options",
           ],
         }
       )

packages/medusa/src/api/routes/store/shipping-options/list-shipping-options.js

@@ -37,13 +37,7 @@ export default async (req, res) => {
 
     const cart = await cartService.retrieve(value.cart_id, {
       select: ["subtotal"],
-      relations: [
-        "region",
-        "items",
-        "items.variant",
-        "items.variant.product",
-        "custom_shipping_options",
-      ],
+      relations: ["region", "items", "items.variant", "items.variant.product"],
     })
 
     const options = await shippingProfileService.fetchCartOptions(cart)