.arcconfig

perf: add a no-lookup variant to perfindex

It is useful to check how long it takes to create a index object without doing
anything with it. We add a new flag dedicated to that.

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