When deleting a workflow the prompt indicates that nodes with the selected workflow will have their workflow states deleted. However after deleting the workflow the entries for that workflow still exist in workflow_states.
We didn't actually test if workflow_node was cleaned up, we only noticed that the entries in workflow_states remain after workflow deletion.
How to reproduce;
1. create a workflow
2. add a state
3. notice new entry in workflow_states
4. delete the workflow
5. notice the associated workflow state(s) are still in workflow_states