[RELAY][PY] Fix relay node registration after refactor (#5083)

python/tvm/relay/op/op_attrs.py

@@ -43,10 +43,12 @@ class Conv2DWinogradWeightTransformAttrs(Attrs):
 class Conv2DWinogradNNPACKWeightTransformAttrs(Attrs):
     """Attributes for nn.contrib_conv2d_winograd_nnpack_weight_transform"""
 
-@register_relay_attr_node
+
+@tvm._ffi.register_object("relay.attrs.Dilation2DAttrs")
 class Dilation2DAttrs(Attrs):
     """Attributes for nn.dilation2d"""
 
+
 @tvm._ffi.register_object("relay.attrs.GlobalPool2DAttrs")
 class GlobalPool2DAttrs(Attrs):
     """Attributes for nn.global_pool"""