[Bug] Infrequent polling test not properly skipped during time skipping

[cretz]

Describe the bug

#152 added test_infrequent_polling_workflow, but put

    if not env.supports_time_skipping:
        pytest.skip("Too slow to test with time-skipping disabled")

when likely meant

    if env.supports_time_skipping:
        pytest.skip("Too slow to test with time-skipping disabled")