.arcconfig

match: drop support for passing '.' for root dir to visit*() methods

We said we'd drop support for it after 5.1, so it's time to clean it
up now.

Differential Revision: https://phab.mercurial-scm.org/D7249

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