Make FSM workloads able to be run via burn_in_tests.py (with --repeat=2)

Individual FSM workloads are not designed to clean up after themselves - rather, they expect the runners to take care of that. This can be problematic when you create or modify a workload, as that is picked up by burn_in_tests, which runs that workload several times without evident cleanup between runs. As a result, that test can conflict with itself (e.g. trying to create a database that already exists by the second run).