Avoid a deprecation warning in graphite2

As of graphite2 1.3.7, `gr_make_face` is deprecated in favor of
`gr_make_face_with_ops`. It's a one-liner to port over to using it.

This is potentially a compatibility break since I'm not sure when the
`with_ops` API was added, but the minimum version of graphite2 that's
supported by Harfbuzz doesn't seem to be documented anywhere anyway.
1 file changed