Move provisioning proxy steps to the new LSO endpoint

Move away from GÉANT-specific API endpoints in LSO, and instead make use of the generic one

gso/workflows/iptrunk/migrate_iptrunk.py

@@ -7,7 +7,6 @@ configured to run from A to C. B is then no longer associated with this IP trunk
 import copy
 import json
 import re
-from logging import getLogger
 from typing import NoReturn
 from uuid import uuid4
 
@@ -41,10 +40,6 @@ from gso.utils.helpers import (
 )
 from gso.utils.workflow_steps import set_isis_to_90000
 
-logger = getLogger(__name__)
-
-PLAYBOOK_VERB_NOT_YET_PROPERLY_SET = "Playbook verb is not yet properly set."
-
 
 def initial_input_form_generator(subscription_id: UUIDstr) -> FormGenerator:
     """Gather input from the operator on the new router that the IP trunk should connect to."""