Replace `xmlrunner` package with `unittest-xml-reporting`

Any unittest.subTest which fails will fail to generate an XML report with the following error:

2022-10-26 12:03:36,615 - Traceback (most recent call last):                                                                                                                                                                                                               
  File "/var/lib/irods/scripts/run_tests.py", line 206, in <module>                                                                   
    results = run_tests_from_names(test_identifiers, options.buffer_test_output, options.xml_output, options.skip_until)            
  File "/var/lib/irods/scripts/run_tests.py", line 127, in run_tests_from_names  
    results = runner.run(super_suite)                                                                               
  File "/usr/local/lib/python3.8/dist-packages/xmlrunner/xmlrunner.py", line 421, in run           
    result.printErrors()                                                                                                            
  File "/usr/lib/python3.8/unittest/runner.py", line 110, in printErrors                                           
    self.printErrorList('FAIL', self.failures)                                                                                           
  File "/usr/local/lib/python3.8/dist-packages/xmlrunner/xmlrunner.py", line 217, in printErrorList                                          
    '%s [%.3fs]: %s' % (flavour, test_info.elapsed_time,                                                                                                                                                           
AttributeError: '_SubTest' object has no attribute 'elapsed_time'

It seems that simply replacing the package resolves the issue: https://github.com/xmlrunner/unittest-xml-reporting/issues/218#issuecomment-665088941

irods / irods_testing_environment

Replace `xmlrunner` package with `unittest-xml-reporting` #127