base-revsets: use an author that actually exercises a lot of changesets This was caught in my big find-and-replace: d4ba4d51f85f. The point of `base-revsets` is to give revsets that will give a good coverage of the repository. Using Pierre-Yves as the second largest committer (in terms of number of changesets) seems like a good idea.

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