Preliminary support for Python 3.13a3

[icemac]

Open issues:

• [X] Fixes #55 – replace deprecated C function
• [x] Error in test test_cant_persist_acquisition_wrappers_classic (Acquisition.tests.TestPickle.test_cant_persist_acquisition_wrappers_classic) Traceback (most recent call last): File "/Library/Frameworks/Python.framework/Versions/3.13/lib/python3.13/unittest/case.py", line 58, in testPartExecutor yield File "/Library/Frameworks/Python.framework/Versions/3.13/lib/python3.13/unittest/case.py", line 636, in run self._callTestMethod(testMethod) File "/Library/Frameworks/Python.framework/Versions/3.13/lib/python3.13/unittest/case.py", line 589, in _callTestMethod if method() is not None: File "/Users/runner/work/Acquisition/Acquisition/src/Acquisition/tests.py", line 1520, in test_cant_persist_acquisition_wrappers_classic pickler.persistent_id = persistent_id AttributeError: '_pickle.Pickler' object attribute 'persistent_id' is read-only
• [x] Error in test test_cant_persist_acquisition_wrappers_newstyle (Acquisition.tests.TestPickle.test_cant_persist_acquisition_wrappers_newstyle) Traceback (most recent call last): File "/Library/Frameworks/Python.framework/Versions/3.13/lib/python3.13/unittest/case.py", line 58, in testPartExecutor yield File "/Library/Frameworks/Python.framework/Versions/3.13/lib/python3.13/unittest/case.py", line 636, in run self._callTestMethod(testMethod) File "/Library/Frameworks/Python.framework/Versions/3.13/lib/python3.13/unittest/case.py", line 589, in _callTestMethod if method() is not None: File "/Users/runner/work/Acquisition/Acquisition/src/Acquisition/tests.py", line 1579, in test_cant_persist_acquisition_wrappers_newstyle pickler.persistent_id = persistent_id AttributeError: '_pickle.Pickler' object attribute 'persistent_id' is read-only

[icemac]

Note: I personally do not plan to work on fixing these tests.

[davisagli]

@icemac I added a proposed fix for the failing tests on Python 3.13.0a3

[icemac]

@davisagli Thank you for fixing the tests.

[icemac]

Thank you for working on resp. reviewing this PR. 😃

[icemac]

Hm, https://github.com/zopefoundation/zope.copy/issues/15 shows a similar traceback but there it seems to be in the actual code instead of beeing just in the tests.