Remove StopJob test workaround

[ysimonson]

We currently have a workaround in the tests due to an ergonomics issue in StopJob. We should address this in tests once the StopJob issue is fixed: pachyderm/pachyderm#3856

python-pachyderm/tests/test_pps.py

Lines 64 to 70 in bbf2d25

	# This is necessary because `StopJob` does not wait for the job to be
	# killed before returning a result.
	# TODO: remove once this is fixed:
	# https://github.com/pachyderm/pachyderm/issues/3856
	time.sleep(1)
	job = sandbox.client.inspect_job(job_id)
	assert job.state == python_pachyderm.JobState.JOB_KILLED.value