fix(examples): fix diagram in average across bodies example

Author: PProfizi

examples/09-averaging/01-average_across_bodies.py

@@ -91,7 +91,7 @@
 #       ds [label="data_src", shape=box, style=filled, fillcolor=cadetblue2];
 #       stress [label="stress"];
 #       scp [label="split_on_property_type"];
-#       eln_to_n ["elemental_nodal_to_nodal_fc"];
+#       eln_to_n [label="elemental_nodal_to_nodal_fc"];
 #       vm [label="eqv_fc"];
 #       avg [label="weighted_merge_fields_by_label"];
 #       subgraph cluster_1 {