FIX: Remove force_path_ccw of contours

This was added to fix previously unoriented paths from Matplotlib's
contouring code. This has seemingly been fixed upstream somewhere
in the past and there is no test/reproducer in Cartopy, so we
can remove this for now.

lib/cartopy/mpl/geoaxes.py

@@ -171,12 +171,7 @@ def transform_path_non_affine(self, src_path):
             return mpath.Path(self.transform(src_path.vertices))
 
         transformed_geoms = []
-        # Check whether this transform has the "force_path_ccw" attribute set.
-        # This is a cartopy extension to the Transform API to allow finer
-        # control of Path orientation handling (Path ordering is not important
-        # in matplotlib, but is in Cartopy).
-        geoms = cpatch.path_to_geos(src_path,
-                                    getattr(self, 'force_path_ccw', False))
+        geoms = cpatch.path_to_geos(src_path)
 
         for geom in geoms:
             proj_geom = self.target_projection.project_geometry(
@@ -1642,12 +1637,6 @@ def contourf(self, *args, **kwargs):
         t = kwargs.get('transform')
         if isinstance(t, ccrs.Projection):
             kwargs['transform'] = t = t._as_mpl_transform(self)
-        # Set flag to indicate correcting orientation of paths if not ccw
-        if isinstance(t, mtransforms.Transform):
-            for sub_trans, _ in t._iter_break_from_left_to_right():
-                if isinstance(sub_trans, InterProjectionTransform):
-                    if not hasattr(sub_trans, 'force_path_ccw'):
-                        sub_trans.force_path_ccw = True
 
         result = super().contourf(*args, **kwargs)