Updating to the current highest number instead of making it the default
which is highest know by the language. This is beacuse when we update
between python versions if there is a new proctocol version, we don't
want that to cause cache thrashing as we try to load things from the
various caches. We can get into a situation where new machines pickle
things with a newer versions of the procotocl, put them in the cache and
then break older machines that don't know about the new protocol
version.
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