Tests fail on 3.13a1

[icemac]

The tests fail on Python 3.13a1, see
https://github.com/zopefoundation/zope.testrunner/actions/runs/6767286602/job/18389668025?pr=154

[d-maurer]

Michael Howitz wrote at 2023-11-5 22:53 -0800:

The tests fail on Python 3.13a1, see https://github.com/zopefoundation/zope.testrunner/actions/runs/6767286602/job/18389668025?pr=154

I have seen an issue report explaining Python 3.13 test related problems: Python 3.13 strips (some) whitespace from "docstring"s potentially with an effect to "doctest"s. Hopefully, Python's `doctest` module will (eventually) come with a normalizer making this whitespace removal transparent. Otherwise, we likely would need to employ such a normalizer (in many `zopefoundation` projects).

[dataflake]

The tests are now green, calling this resolved.