urlutil: inline the relevant part of `getpath` in `get_push_paths`
The part that `get_push_paths` needs is quite simple, inclining will help us
to deprecated `getpath`.
Differential Revision: https://phab.mercurial-scm.org/D10438
{
"conduit_uri": "https://phab.mercurial-scm.org/api",
"phabricator.uri": "https://phab.mercurial-scm.org/",
"repository.callsign": "HG",
"arc.land.onto.default": "@",
"base": "hg:.^"
}