[Bug] Support for Python 3.12 - Missing distutils

Start by reproducing the import failure with Python 3.12 and trace the dependency chain through mitreattack/collections/stix_to_collection.py, stix2elevator, stix, and mixbox/parser.py. Review related issue 163 to determine whether removing STIX1 support is the intended direction; done means the library imports successfully under Python 3.12 without the missing distutils module.

Expected Behavior

The library should function under Python3.12

Actual Behavior

The library attempts to load the distutils module, which was removed in Python3.12. See https://docs.python.org/3.10/library/distutils.html for background on the deprecation and removal of distutils.

Steps to Reproduce the Problem

1. Install mitreattack-python with python3 -m pip install mitreattack-python
2. Run python3 and attempt to load library:

% python3 --version
Python 3.12.4

% python3
Python 3.12.4 (main, Jun  6 2024, 18:26:44) [Clang 15.0.0 (clang-1500.3.9.4)] on darwin
Type "help", "copyright", "credits" or "license" for more information.

>>> from mitreattack.navlayers.core import Layer

Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
  File "/Users/jessek/tmp/lib/python3.12/site-packages/mitreattack/__init__.py", line 3, in <module>
    from .collections import *
  File "/Users/jessek/tmp/lib/python3.12/site-packages/mitreattack/collections/__init__.py", line 3, in <module>
    from .stix_to_collection import *
  File "/Users/jessek/tmp/lib/python3.12/site-packages/mitreattack/collections/stix_to_collection.py", line 9, in <module>
    from stix2elevator.stix_stepper import step_bundle
  File "/Users/jessek/tmp/lib/python3.12/site-packages/stix2elevator/__init__.py", line 12, in <module>
    from stix.core import STIXPackage
  File "/Users/jessek/tmp/lib/python3.12/site-packages/stix/__init__.py", line 5, in <module>
    from .base import (Entity, EntityList, TypedCollection, TypedList,  # noqa
  File "/Users/jessek/tmp/lib/python3.12/site-packages/stix/base.py", line 20, in <module>
    from . import utils
  File "/Users/jessek/tmp/lib/python3.12/site-packages/stix/utils/__init__.py", line 382, in <module>
    from .parser import *  # noqa
    ^^^^^^^^^^^^^^^^^^^^^
  File "/Users/jessek/tmp/lib/python3.12/site-packages/stix/utils/parser.py", line 7, in <module>
    import mixbox.parser
  File "/Users/jessek/tmp/lib/python3.12/site-packages/mixbox/parser.py", line 5, in <module>
    from distutils.version import StrictVersion
ModuleNotFoundError: No module named 'distutils'

>>>

Possible Solution

This may be related to https://github.com/mitre-attack/mitreattack-python/issues/163, and removing support for STIX1 will remove the dependency.