cloudpickle is not compatible with PyPy 7.3.22

[Viicos]

PyPy 7.3.22 shipped with a large refactor of the pickle module in pypy/pypy#5403. Importing cloudpickle now fails with:

venv/lib/pypy3.11/site-packages/cloudpickle/__init__.py:1: in <module>
    from . import cloudpickle
.venv/lib/pypy3.11/site-packages/cloudpickle/cloudpickle.py:1224: in <module>
    class Pickler(pickle.Pickler):
.venv/lib/pypy3.11/site-packages/cloudpickle/cloudpickle.py:1406: in Pickler
    dispatch = pickle.Pickler.dispatch.copy()
E   AttributeError: type object 'Pickler' has no attribute 'dispatch'

Example job.

[mattip]

The refactor supplies, like CPython, a _pickle compiled module. So I think the check here

cloudpickle/cloudpickle/cloudpickle.py

Line 1337 in f5199fe

if not PYPY:

should be more nuanced and check that _pickle is not being used.

BTW, feel free to ping me on future PyPy problems. I only found this because someone opened pypy/pypy#5481