chore: fix linting

scenario/mocking.py

@@ -632,7 +632,7 @@ def resource_get(self, resource_name: str) -> str:
             )
 
     def credential_get(self) -> CloudSpec:
-        if not self._cloud_spec:
+        if not self._state.cloud_spec:
             raise ModelError(
                 "ERROR cloud spec is empty, initialise it with `scenario.State(cloud_spec=...)`",
             )