fix(utils): medusa internal service returned data should match typings (#12715)

FIXES SUP-1824

**What**
The medusa internal service update should always return the data in the expected shape described by the interface. The medusa service should not have to handle the reshapre

packages/modules/inventory/src/services/inventory-module.ts

@@ -1052,7 +1052,7 @@ export default class InventoryModuleService
       context
     )
 
-    return result[0]
+    return result
   }
 
   @InjectManager()