vendored packages are out of date

[jaraco]

A lot has changed since the vendored packages were last updated. Attempting to update them leads to some failures like:

  File "/Users/jaraco/code/pypa/setuptools/setuptools/_vendor/jaraco/functools/__init__.py", line 10, in <module>
    import more_itertools
ModuleNotFoundError: No module named 'more_itertools'

It's probably time to refresh the vendored dependencies.

[jaraco]

I tried pushing the fix, but it breaks all over the place, so I've created a PR to track.