largefiles: migrate to scmutil.backuppath() It seems unnecessary to convert the paths here back to repo-relative paths, but I'll leave that for someone else to clean up. Differential Revision: https://phab.mercurial-scm.org/D5854

{
    "conduit_uri": "https://phab.mercurial-scm.org/api",
    "repository.callsign": "HG",
    "arc.land.onto.default": "@",
    "base": "hg:.^"
}