chore(oas): update order OAS schema to include new fields (#5436)

www/apps/api-reference/specs/admin/components/schemas/Order.yaml

@@ -263,6 +263,11 @@ properties:
     type: integer
     description: The total of shipping
     example: 1000
+    nullable: true
+  shipping_tax_total:
+    type: integer
+    description: The tax total applied on shipping
+    example: 1000
   raw_discount_total:
     description: The total of discount
     type: integer
@@ -275,6 +280,11 @@ properties:
     description: The total of tax
     type: integer
     example: 0
+  item_tax_total:
+    description: The tax total applied on items
+    type: integer
+    example: 0
+    nullable: true
   refunded_total:
     description: The total amount refunded if the order is returned.
     type: integer