feat: Pricing update and refactor product API tests to not rely on internals (#6892)

This PR achieves the following
- Remove dependency on internals for seeding the tests (more work left, but major work done)
- Adds the workflow for updating variant's price

I will do a follow-up PR to further clean up the tests and remove all internal dependencies

packages/product/src/services/product-module-service.ts

@@ -1108,7 +1108,7 @@ export default class ProductModuleService<
     const productData = await this.productService_.upsertWithReplace(
       normalizedInput,
       {
-        relations: ["type", "collection", "images", "tags", "categories"],
+        relations: ["images", "tags", "categories"],
       },
       sharedContext
     )
@@ -1164,7 +1164,7 @@ export default class ProductModuleService<
     const productData = await this.productService_.upsertWithReplace(
       normalizedInput,
       {
-        relations: ["type", "collection", "images", "tags", "categories"],
+        relations: ["images", "tags", "categories"],
       },
       sharedContext
     )
@@ -1350,6 +1350,10 @@ export default class ProductModuleService<
         }
       )
 
+      if (!variantOptions.length) {
+        return variant
+      }
+
       return {
         ...variant,
         options: variantOptions,