Update type hints such that APIItemInfo.product_info is optional to match Amazon responses.

Author: YPCrumble

amazon_paapi/models/item_result.py

@@ -1,4 +1,4 @@
-from typing import List
+from typing import List, Optional
 
 from ..sdk import models
 
@@ -148,7 +148,7 @@ class ApiItemInfo(models.ItemInfo):
     external_ids: ApiExternalIds
     features: ApiFeatures
     manufacture_info: ApiManufactureInfo
-    product_info: ApiProductInfo
+    product_info: Optional[ApiProductInfo]
     technical_info: ApiTechnicalInfo
     title: ApiSingleStringValuedAttribute
     trade_in_info: ApiTradeInInfo