chore(language): delete sample language_python_migration_imports (#12817)

Author: eapl-gemugami

language/snippets/cloud-client/v1/quickstart.py

@@ -18,10 +18,8 @@
 def run_quickstart():
     # [START language_quickstart]
     # Imports the Google Cloud client library
-    # [START language_python_migration_imports]
     from google.cloud import language_v1
 
-    # [END language_python_migration_imports]
     # Instantiates a client
     # [START language_python_migration_client]
     client = language_v1.LanguageServiceClient()