Python 3.11.5 fails with stix-shifter interface

[subbyte]

Describe the bug
Unit test hangs for anything that uses stix-shifter, e.g., test_cli.py or test_command_get.py::test_get_single_stixshifter_stix_bundle.

Details of the bug

Process TransmitterPool-3:
Traceback (most recent call last):
  File "/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/multiprocessing/process.py", line 314, in _bootstrap
    self.run()
  File "/Users/subx/venv/py311/lib/python3.11/site-packages/kestrel_datasource_stixshifter/worker/transmitter.py", line 53, in run
    transmitter.start()
  File "/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/multiprocessing/process.py", line 121, in start
    self._popen = self._Popen(self)
                  ^^^^^^^^^^^^^^^^^
  File "/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/multiprocessing/context.py", line 224, in _Popen
    return _default_context.get_context().Process._Popen(process_obj)
           ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/multiprocessing/context.py", line 288, in _Popen
    return Popen(process_obj)
           ^^^^^^^^^^^^^^^^^^
  File "/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/multiprocessing/popen_spawn_posix.py", line 32, in __init__
    super().__init__(process_obj)
  File "/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/multiprocessing/popen_fork.py", line 19, in __init__
    self._launch(process_obj)
  File "/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/multiprocessing/popen_spawn_posix.py", line 47, in _launch
    reduction.dump(process_obj, fp)
  File "/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/multiprocessing/reduction.py", line 60, in dump
    ForkingPickler(file, protocol).dump(obj)
  File "/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/multiprocessing/synchronize.py", line 106, in __getstate__
    if self.is_fork_ctx:
       ^^^^^^^^^^^^^^^^
AttributeError: 'Lock' object has no attribute 'is_fork_ctx'

To Reproduce
pytest

Expected behavior
No error.

Environment (please complete the following information):

• Kestrel 1.7.5
• macOS
• Python 3.11.5 (latest as of 2023/09/12)

Solution
This looks like a bug in Python multiprocessing library: python/cpython#108520 and it is already solved and await to be released in the next Python version.

[subbyte]

Confirmed that Python 3.11.4 works on macOS

[subbyte]

Confirmed resolved with Python 3.11.6 (released Oct 2, 2023).

[subbyte]

Specify 3.11.6 for unit test (github workflow) of test-kestrel-datasource-stixshifter. Please remove the .6 suffix when it is the default env for Python 3.11 in github action (probably when 3.11.7 is released).

[subbyte]

Done in #502