`TESBatchSystemTest` tests are flaky

[stxue1]

The TESBatchSystemTest.test_set_job_env sometimes fails on CI https://ucsc-ci.com/databiosphere/toil/-/jobs/54265

_____________________ TESBatchSystemTest.test_set_job_env ______________________
[gw0] linux -- Python 3.9.18 /builds/databiosphere/toil/venv/bin/python
Traceback (most recent call last):
  File "/usr/lib/python3.9/unittest/case.py", line 59, in testPartExecutor
    yield
  File "/usr/lib/python3.9/unittest/case.py", line 592, in run
    self._callTestMethod(testMethod)
  File "/usr/lib/python3.9/unittest/case.py", line 550, in _callTestMethod
    method()
  File "/builds/databiosphere/toil/src/toil/test/batchSystems/batchSystemTest.py", line 291, in test_set_job_env
    self.assertEqual(job_update_info.exitStatus, 23)  # this should succeed
AttributeError: 'NoneType' object has no attribute 'exitStatus'

The TESBatchSystemTest.test_set_env also fails sometimes https://ucsc-ci.com/databiosphere/toil/-/jobs/53998

_______________________ TESBatchSystemTest.test_set_env ________________________
[gw0] linux -- Python 3.9.16 /builds/databiosphere/toil/venv/bin/python
Traceback (most recent call last):
  File "/usr/lib/python3.9/unittest/case.py", line 59, in testPartExecutor
    yield
  File "/usr/lib/python3.9/unittest/case.py", line 592, in run
    self._callTestMethod(testMethod)
  File "/usr/lib/python3.9/unittest/case.py", line 550, in _callTestMethod
    method()
  File "/builds/databiosphere/toil/src/toil/test/batchSystems/batchSystemTest.py", line 267, in test_set_env
    jobID, exitStatus, wallTime = jobUpdateInfo.jobID, jobUpdateInfo.exitStatus, jobUpdateInfo.wallTime
AttributeError: 'NoneType' object has no attribute 'jobID'

┆Issue is synchronized with this Jira Story ┆Issue Number: TOIL-1426