MNT: Mark some mapping tests as xfail on Cartopy 0.23.0

This is due to SciTools/cartopy#2377, which has been fixed upstream and
will be in the next release.

tests/plots/test_mapping.py

@@ -8,6 +8,7 @@
 ccrs = pytest.importorskip('cartopy.crs')
 
 from metpy.plots.mapping import CFProjection  # noqa: E402
+from metpy.testing import version_check
 
 
 def test_inverse_flattening_0():
@@ -147,13 +148,15 @@ def test_lcc():
     assert crs.globe.to_proj4_params()['ellps'] == 'sphere'
 
 
+@pytest.mark.xfail(version_check('cartopy==0.23.0'), reason='SciTools/cartopy#2377')
 def test_lcc_minimal():
     """Test handling lambert conformal conic projection with minimal attributes."""
     attrs = {'grid_mapping_name': 'lambert_conformal_conic'}
     crs = CFProjection(attrs).to_cartopy()
     assert isinstance(crs, ccrs.LambertConformal)
 
 
+@pytest.mark.xfail(version_check('cartopy==0.23.0'), reason='SciTools/cartopy#2377')
 def test_lcc_single_std_parallel():
     """Test lambert conformal projection with one standard parallel."""
     attrs = {'grid_mapping_name': 'lambert_conformal_conic', 'standard_parallel': 25}