fix(retail): add region tag for Python - Update get_product.py (#13447)

* Update search_with_pagination.py

* Update get_product.py

Author: rebeccaellis

retail/interactive-tutorials/product/get_product.py

@@ -15,6 +15,7 @@
 
 # Get product from a catalog using Retail API.
 #
+# [START retail_get_product]
 import random
 import string
 
@@ -55,3 +56,4 @@ def get_product(product_name: str):
 product = get_product(created_product.name)
 # remove created product
 delete_product(created_product.name)
+# [END retail_get_product]