multi=False causes Errno 29 illegal seek during pytest teardown

[donaldcampbelljr]

          Reproduce by setting the multi flag to false or just leaving it out:

def test_temp_test():
    pp = pypiper.PipelineManager(
        "sample_pipeline", outfolder="/home/drc/Downloads/BED_CLASSIFIER_OUTPUT/", multi=True
    )

If you set the flag multi=True, it works fine and we no longer get the illegal seek error.

Originally posted by @donaldcampbelljr in https://github.com/databio/bedboss/issues/30#issuecomment-1944492602