Matt Harbison <matt_harbison@yahoo.com> [Mon, 13 Dec 2021 00:04:53 -0500] rev 48516
pytype: stop excluding copies.py
I can't prove that `targetrev` is always in `all_copies`, but it would have been
a runtime error before too if it's not.
Differential Revision: https://phab.mercurial-scm.org/D11916