rust-filepatterns: fix type of warnings tuple to (bytes, bytes)
Otherwise warn() in match.py would fail if the warning contains non-ASCII
character.
We might want to add a thin ByteString wrapper around Vec<u8> to
implement ToPyObject<ObjectType = PyBytes>, but I'm not sure.
{
"conduit_uri": "https://phab.mercurial-scm.org/api",
"repository.callsign": "HG",
"arc.land.onto.default": "@",
"base": "hg:.^"
}