.arcconfig

hg: don't attempt to extend `sys.path` with the user site without `APPDATA`

This variable is created by the system and *should* be available, but
test-lfs-bundle.t has a test where it is explicitly unset.  It wasn't caught
before because prior to 95af358fcdfe, it was limited to the py2exe binary.  As a
precaution, fix both that and the pyoxidizer case that was causing the test to
fail.

Differential Revision: https://phab.mercurial-scm.org/D11354

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