[gtk+] Update to include upstreamed patch
Add a patch to Cairo so that it will respect cairo_set_antialias()
when rendering text with Pango.

The antialias state was no longer making its way down to (what is now)
_cairo_quartz_cg_glyphs().  I'm not sure this is the correct solution
long-term, as I think maybe what we really want to do is set the
cairo_font_options_t and pass it down with the scaled_font.  I'll have
to consult with some upstream people, but in the mean time I think this
will solve https://bugzilla.xamarin.com/show_bug.cgi?id=13540