remove outdated exception

Author: leo-collins

firedrake/interpolation.py

@@ -329,9 +329,7 @@ def get_interpolator(expr: Interpolate) -> Interpolator:
         if isinstance(source_topology, VertexOnlyMeshTopology):
             return VomOntoVomInterpolator(expr)
         if target_mesh.geometric_dimension != source_mesh.geometric_dimension:
-            raise ValueError("Cannot interpolate onto a mesh of a different geometric dimension")
-        if not hasattr(target_mesh, "_parent_mesh") or target_mesh._parent_mesh is not source_mesh:
-            raise ValueError("Can only interpolate across meshes where the source mesh is the parent of the target")
+            raise ValueError("Cannot interpolate onto a VertexOnlyMesh of a different geometric dimension.")
         return SameMeshInterpolator(expr)
 
     if has_mixed_arguments or len(expr.target_space) > 1: