chore: Update region tags (GoogleCloudPlatform#11935)

* chore: Update region tags

Removing unused region tags not associated with a product and not used in documentation.

Sample code that is part of a larger sample is remaining in this file.

Adding product prefix to wait_for_operation as it is referenced in documentation.

* 🦉 Updates from OwlBot post-processor

See https://github.com/googleapis/repo-automation-bots/blob/main/packages/owl-bot/README.md

---------

Co-authored-by: Owl Bot <gcf-owl-bot[bot]@users.noreply.github.com>

Author: arbrown

compute/api/create_instance.py

@@ -31,7 +31,6 @@
 import googleapiclient.discovery
 
 
-# [START list_instances]
 def list_instances(
     compute: object,
     project: str,
@@ -51,9 +50,6 @@ def list_instances(
     return result["items"] if "items" in result else None
 
 
-# [END list_instances]
-
-
 # [START compute_create_instance]
 # [START create_instance]
 def create_instance(
@@ -146,7 +142,6 @@ def create_instance(
 # [END compute_create_instance]
 
 
-# [START delete_instance]
 def delete_instance(
     compute: object,
     project: str,
@@ -169,9 +164,7 @@ def delete_instance(
     )
 
 
-# [END delete_instance]
-
-
+# [START compute_wait_for_operation]
 # [START wait_for_operation]
 def wait_for_operation(
     compute: object,
@@ -208,9 +201,9 @@ def wait_for_operation(
 
 
 # [END wait_for_operation]
+# [END compute_wait_for_operation]
 
 
-# [START run]
 def main(
     project: str,
     bucket: str,
@@ -274,4 +267,3 @@ def main(
     args = parser.parse_args()
 
     main(args.project_id, args.bucket_name, args.zone, args.name)
-# [END run]