Fix T98328: missing depsgraph update after adding node group

Adding node groups can change depsgraph relations, so the depsgraph
has to be rebuild.

source/blender/editors/space_node/node_add.cc

@@ -371,6 +371,7 @@ static int node_add_group_exec(bContext *C, wmOperator *op)
 
   nodeSetActive(ntree, group_node);
   ED_node_tree_propagate_change(C, bmain, nullptr);
+  DEG_relations_tag_update(bmain);
   return OPERATOR_FINISHED;
 }