validate_router: subscription serialization

json_dumps

gso/workflows/router/validate_router.py

 """Router validation workflow. Used in a nightly schedule."""
 
+import json
+
 from orchestrator.targets import Target
 from orchestrator.utils.errors import ProcessFailureError
+from orchestrator.utils.json import json_dumps
 from orchestrator.workflow import StepList, begin, conditional, done, step, workflow
 from orchestrator.workflows.steps import resync, store_process_subscription, unsync
 from orchestrator.workflows.utils import wrap_modify_initial_input_form
@@ -67,7 +70,7 @@ def verify_base_config(subscription: Router, callback_route: str) -> None:
         callback_route=callback_route,
         inventory=subscription.router.router_fqdn,
         extra_vars={
-            "wfo_router_json": subscription,
+            "wfo_router_json": json.loads(json_dumps(subscription)),
             "verb": "deploy",
             "dry_run": "true",
             "is_verification_workflow": "true",