Martin von Zweigbergk <martinvonz@google.com> [Mon, 28 Sep 2020 08:07:09 -0700] rev 45608
updaterepo: add deprecation warning
We just moved all in-tree callers off of the function, but we're
leaving it here for a bit to help extension writers.
Differential Revision: https://phab.mercurial-scm.org/D9110