Assign missing user to context (#9520)

* Remove list from payload. Use camel case for attached meta

* Fix tests

* Assign missing user to context

* Assign context to subscription execute

saleor/graphql/webhook/subscription_payload.py

@@ -85,6 +85,7 @@ def generate_payload_from_subscription(
     generate a payload
     """
     from ..api import schema
+    from ..context import get_context_value
 
     graphql_backend = get_default_backend()
     ast = parse(subscription_query)  # type: ignore
@@ -99,7 +100,7 @@ def generate_payload_from_subscription(
     results = document.execute(
         allow_subscriptions=True,
         root=(event_type, subscribable_object),
-        context=context,
+        context=get_context_value(context),
     )
     if hasattr(results, "errors"):
         logger.warning(