procutil: define LineBufferedWrapper on all Python versions
There’s nothing Python 3-only about LineBufferedWrapper. In the future, we may
want to use it on Windows, to work around missing line-buffering support.
{
"conduit_uri": "https://phab.mercurial-scm.org/api",
"phabricator.uri": "https://phab.mercurial-scm.org/",
"repository.callsign": "HG",
"arc.land.onto.default": "@",
"base": "hg:.^"
}