rhg: Build in release mode on CI
This follows e73b40c790ec which made tests use the release executable.
With e73b40c790ec but not this, tests are skipped on CI
because the executable is missing.
Differential Revision: https://phab.mercurial-scm.org/D9907
# mercurial.revlogutils -- basic utilities for revlog
#
# Copyright 2019 Pierre-Yves David <pierre-yves.david@octobus.net>
#
# This software may be used and distributed according to the terms of the
# GNU General Public License version 2 or any later version.
from __future__ import absolute_import