Fix Python 3.14 for pytest-backend

[ArBridgeman]

When running the unit tests for Python 3.14, we run into a pickling error. This should be investigated and resolved.

=================================== FAILURES ===================================
_______________________________ test_my_brewery ________________________________

    def test_my_brewery():
>       with my_brewery_async() as brewery:
             ^^^^^^^^^^^^^^^^^^

test/unit/test_parallel_task.py:31: 
_ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ 
/opt/hostedtoolcache/Python/3.14.0/x64/lib/python3.14/contextlib.py:141: in __enter__
    return next(self.gen)
           ^^^^^^^^^^^^^^
test/unit/test_parallel_task.py:24: in my_brewery_async
    with brewery_factory(
exasol/pytest_backend/parallel_task.py:43: in __enter__
    self._proc.start()
/opt/hostedtoolcache/Python/3.14.0/x64/lib/python3.14/multiprocessing/process.py:121: in start
    self._popen = self._Popen(self)
                  ^^^^^^^^^^^^^^^^^
/opt/hostedtoolcache/Python/3.14.0/x64/lib/python3.14/multiprocessing/context.py:224: in _Popen
    return _default_context.get_context().Process._Popen(process_obj)
           ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
/opt/hostedtoolcache/Python/3.14.0/x64/lib/python3.14/multiprocessing/context.py:300: in _Popen
    return Popen(process_obj)
           ^^^^^^^^^^^^^^^^^^
/opt/hostedtoolcache/Python/3.14.0/x64/lib/python3.14/multiprocessing/popen_forkserver.py:35: in __init__
    super().__init__(process_obj)
/opt/hostedtoolcache/Python/3.14.0/x64/lib/python3.14/multiprocessing/popen_fork.py:20: in __init__
    self._launch(process_obj)
/opt/hostedtoolcache/Python/3.14.0/x64/lib/python3.14/multiprocessing/popen_forkserver.py:47: in _launch
    reduction.dump(process_obj, buf)
_ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ 

obj = <Process name='Process-1' parent=2756 initial>
file = <_io.BytesIO object at 0x7ff026975c10>, protocol = None

    def dump(obj, file, protocol=None):
        '''Replacement for pickle.dump() using ForkingPickler.'''
>       ForkingPickler(file, protocol).dump(obj)
E       _pickle.PicklingError: Can't pickle <function brewery_factory at 0x7ff026b70930>: it's not the same object as test_parallel_task.brewery_factory
E       when serializing dict item '_ctx_func'
E       when serializing exasol.pytest_backend.parallel_task._ParallelGenCtxManager state
E       when serializing exasol.pytest_backend.parallel_task._ParallelGenCtxManager object
E       when serializing tuple item 0
E       when serializing method reconstructor arguments
E       when serializing method object
E       when serializing dict item '_target'
E       when serializing multiprocessing.context.Process state
E       when serializing multiprocessing.context.Process object

/opt/hostedtoolcache/Python/3.14.0/x64/lib/python3.14/multiprocessing/reduction.py:60: PicklingError
_______________________________ test_div_by_zero _______________________________

    def test_div_by_zero():
        with pytest.raises(RuntimeError) as ex_info:
>           with my_div(10, 0) as my_div_async:
                 ^^^^^^^^^^^^^

test/unit/test_parallel_task.py:48: 
_ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ 
exasol/pytest_backend/parallel_task.py:43: in __enter__
    self._proc.start()
/opt/hostedtoolcache/Python/3.14.0/x64/lib/python3.14/multiprocessing/process.py:121: in start
    self._popen = self._Popen(self)
                  ^^^^^^^^^^^^^^^^^
/opt/hostedtoolcache/Python/3.14.0/x64/lib/python3.14/multiprocessing/context.py:224: in _Popen
    return _default_context.get_context().Process._Popen(process_obj)
           ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
/opt/hostedtoolcache/Python/3.14.0/x64/lib/python3.14/multiprocessing/context.py:300: in _Popen
    return Popen(process_obj)
           ^^^^^^^^^^^^^^^^^^
/opt/hostedtoolcache/Python/3.14.0/x64/lib/python3.14/multiprocessing/popen_forkserver.py:35: in __init__
    super().__init__(process_obj)
/opt/hostedtoolcache/Python/3.14.0/x64/lib/python3.14/multiprocessing/popen_fork.py:20: in __init__
    self._launch(process_obj)
/opt/hostedtoolcache/Python/3.14.0/x64/lib/python3.14/multiprocessing/popen_forkserver.py:47: in _launch
    reduction.dump(process_obj, buf)
_ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ 

obj = <Process name='Process-2' parent=2756 initial>
file = <_io.BytesIO object at 0x7ff029efd210>, protocol = None

    def dump(obj, file, protocol=None):
        '''Replacement for pickle.dump() using ForkingPickler.'''
>       ForkingPickler(file, protocol).dump(obj)
E       _pickle.PicklingError: Can't pickle <function my_div at 0x7ff026995f30>: it's not the same object as test_parallel_task.my_div
E       when serializing dict item '_ctx_func'
E       when serializing exasol.pytest_backend.parallel_task._ParallelGenCtxManager state
E       when serializing exasol.pytest_backend.parallel_task._ParallelGenCtxManager object
E       when serializing tuple item 0
E       when serializing method reconstructor arguments
E       when serializing method object
E       when serializing dict item '_target'
E       when serializing multiprocessing.context.Process state
E       when serializing multiprocessing.context.Process object

/opt/hostedtoolcache/Python/3.14.0/x64/lib/python3.14/multiprocessing/reduction.py:60: PicklingError
=========================== short test summary info ============================
FAILED test/unit/test_parallel_task.py::test_my_brewery - _pickle.PicklingError: Can't pickle <function brewery_factory at 0x7ff026b70930>: it's not the same object as test_parallel_task.brewery_factory
when serializing dict item '_ctx_func'
when serializing exasol.pytest_backend.parallel_task._ParallelGenCtxManager state
when serializing exasol.pytest_backend.parallel_task._ParallelGenCtxManager object
when serializing tuple item 0
when serializing method reconstructor arguments
when serializing method object
when serializing dict item '_target'
when serializing multiprocessing.context.Process state
when serializing multiprocessing.context.Process object
FAILED test/unit/test_parallel_task.py::test_div_by_zero - _pickle.PicklingError: Can't pickle <function my_div at 0x7ff026995f30>: it's not the same object as test_parallel_task.my_div
when serializing dict item '_ctx_func'
when serializing exasol.pytest_backend.parallel_task._ParallelGenCtxManager state
when serializing exasol.pytest_backend.parallel_task._ParallelGenCtxManager object
when serializing tuple item 0
when serializing method reconstructor arguments
when serializing method object
when serializing dict item '_target'
when serializing multiprocessing.context.Process state
when serializing multiprocessing.context.Process object

To Do

• Figure out what is causing the issue
• Resolve issue
• Update pyproject.toml to include Python <4 (not <3.14)
• Remove python_versions defined in PROJECT_CONFIG of noxconfig.py