Import the global polygon as the full polygon

[paleolimbot]

Whatever it's getting imported as now is not correct!

s2::s2_area("POLYGON ((-180 -90, 180 -90, 180 90, -180 90, -180 -90))")
#> [1] 0.009941626

^{Created on 2022-08-15 by the reprex package (v2.0.1)}

This causes problems in sf (and probably elsewhere!): https://github.com/r-spatial/sf/issues/1984