fix(retail): add region tag for Python - Update upate_product.py (#13442)

* Update search_with_pagination.py

* Update update_product.py

* Update update_product.py

* lint

---------

Co-authored-by: Katie McLaughlin <katie@glasnt.com>

Author: rebeccaellis

retail/interactive-tutorials/product/update_product.py

@@ -15,6 +15,7 @@
 
 # Update product in a catalog using Retail API
 #
+# [START retail_update_product]
 import random
 import string
 
@@ -90,3 +91,4 @@ def update_product(original_product: Product):
 update_product(created_product)
 # delete product
 delete_product(created_product.name)
+# [END retail_update_product]