typing: make minor adjustments to mercurial/util.py to pass pytype checking I'm assuming the wrong-arg-count is a pytype bug, because this code is used by the config object. Avoiding initializing `_lrucachenode` node points to None eliminates a few `is not None` assertions, but apparently not all of them. I can't figure out why it gets confused over the state where these new assertions are. Differential Revision: https://phab.mercurial-scm.org/D10276

util: fix the signature for the pypy override of sortdict.update() PyCharm flagged this as not matching the base class signature. Not sure if there was anything supplying these extra arguments though. Differential Revision: https://phab.mercurial-scm.org/D10275