Tests newly failing with Python 3.12

[juliangilbey]

Hi!
Some of the tests fail when using Python 3.12 (probably in addition to those that fail with Python 3.11 - see #240, #257): here is a list of them:

tests_python/test_debugger.py::test_attach_to_pid_halted
tests_python/test_debugger.py::test_case_13
tests_python/test_debugger.py::test_case_handled_and_unhandled_exception_generator[False-_debugger_case_unhandled_exceptions_listcomp.py]
tests_python/test_debugger.py::test_remote_debugger_threads
tests_python/test_debugger_json.py::test_case_unhandled_exception_generator[_debugger_case_unhandled_exceptions_listcomp.py]
tests_python/test_utilities.py::test_tracing_basic
tests_python/test_utilities.py::test_tracing_other_threads

(The test logs are very long, so I'm not attaching them here.)

[juliangilbey]

And possibly due to upgraded gevent (to 23.9.1) or greenlet (to 3.0.1), there are further failures on 3.12:

FAILED tests_python/test_debugger.py::test_gevent
FAILED tests_python/test_debugger.py::test_gevent_remote
FAILED tests_python/test_debugger_json.py::test_wait_for_attach_gevent
FAILED tests_python/test_debugger_json.py::test_gevent_show_paused_greenlets[True]
FAILED tests_python/test_debugger_json.py::test_gevent_subprocess_not_python
FAILED tests_python/test_debugger_json.py::test_gevent_subprocess_python