Depsgraph: Stop tagging all IDs for update on depsgraph rebuild

This code needs to be changed. For the time being CoW might become less stable,
but need to stop doing such tag for other work.

source/blender/depsgraph/intern/builder/deg_builder.cc

@@ -61,11 +61,6 @@ void deg_graph_build_finalize(Depsgraph *graph)
 				id_node->tag_update(graph);
 			}
 		}
-		/* XXX: This is only so we've got proper COW IDs after rebuild. */
-		/* TODO(sergey): Ideally we'll need to copy evaluated CoW from previous
-		 * depsgraph, so we don't need to re-tag anything what we already have.
-		 */
-		id_node->tag_update(graph);
 	}
 	GHASH_FOREACH_END();
 }