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 evolves over time, some features, options, commands may be replaced by
better and more secure alternatives. This topic will help you migrating your
existing usage and/or configuration to newer features.
Commands
========
The following commands are still available but their use are not recommended:
``locate``
This command has been replaced by `hg files`.
``parents``
This command can be replaced by `hg summary` or `hg log` with appropriate
revsets. See `hg help revsets` for more information.
``tip``
The recommended alternative is `hg heads`.
Options
=======
``web.allowpull``
Renamed to `allow-pull`.
``web.allow_push``
Renamed to `allow-push`.