Fix Python 3.13 compatibility (ST 4201)

[themilkman]

The latest ST 4201, which replaces py38 with py313, has been released as a private beta in the discord. See discord.com/channels/280102180189634562/650695903446827011/1432613579223339059

AnyTest has an import error with py313 because distutils has been removed (see: https://peps.python.org/pep-0632/#migration-advice)

Traceback (most recent call last):
  File "/opt/sublime_text/Lib/python313/sublime_plugin.py", line 316, in reload_plugin
    m = importlib.import_module(modulename)
  File "./python3.13/importlib/__init__.py", line 88, in import_module
  File "<frozen importlib._bootstrap>", line 1387, in _gcd_import
  File "<frozen importlib._bootstrap>", line 1360, in _find_and_load
  File "<frozen importlib._bootstrap>", line 1331, in _find_and_load_unlocked
  File "<frozen importlib._bootstrap>", line 935, in _load_unlocked
  File "<frozen importlib._bootstrap_external>", line 1052, in exec_module
  File "<frozen importlib._bootstrap>", line 488, in _call_with_frames_removed
  File "/home/me/.config/sublime-text-3/Installed Packages/AnyTest.sublime-package/main.py", line 18, in <module>
    from .plugin import SCOPE_LAST, Plugin  # noqa: E402
    ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/home/me/.config/sublime-text-3/Installed Packages/AnyTest.sublime-package/plugin/__init__.py", line 6, in <module>
    from . import cache, runners, settings, status, test_frameworks
  File "/home/me/.config/sublime-text-3/Installed Packages/AnyTest.sublime-package/plugin/test_frameworks/__init__.py", line 6, in <module>
    from .. import errors, settings, utils
  File "/home/me/.config/sublime-text-3/Installed Packages/AnyTest.sublime-package/plugin/utils.py", line 2, in <module>
    from distutils import spawn
ModuleNotFoundError: No module named 'distutils'

This PR replaces distutils with shutil as suggested in the pep above. With that, the plugin works now here. Disclaimer: I am not really a Python dev, so please take a close look on this before merging ;)

Moreover I do not know whether this will work with ST versions < 4201, thus the next release might better target 4201+.

And finally, thanks for AnyTest, I use it nearly daily for Ruby - a great tool!

[FichteFoll]

shutil.which was added in Python 3.3, so should be fine for any non-ST2 version.

[timfjord]

Great, thanks for the contribution @themilkman