chore: add region tag for IAM auth connection code (#147)

Author: shubha-rajan

tests/system/test_pg8000_iam_auth.py

@@ -25,6 +25,9 @@
 table_name = f"books_{uuid.uuid4().hex}"
 
 
+# [START cloud_sql_connector_postgres_pg8000_iam_auth]
+# The Cloud SQL Python Connector can be used along with SQLAlchemy using the
+# 'creator' argument to 'create_engine'
 def init_connection_engine() -> sqlalchemy.engine.Engine:
     def getconn() -> pg8000.dbapi.Connection:
         conn: pg8000.dbapi.Connection = connector.connect(
@@ -44,6 +47,9 @@ def getconn() -> pg8000.dbapi.Connection:
     return engine
 
 
+# [END cloud_sql_connector_postgres_pg8000_iam_auth]
+
+
 @pytest.fixture(name="pool")
 def setup() -> Generator:
     pool = init_connection_engine()