The `GeoTreeLog::ensure_evaluated_gizmo_nodes()` reran the iteration
over the tree loggers to add the node ids for the evaluated gizmo.
This wasn't an issue because `GeoTreeLog::evaluated_gizmo_nodes` is
a set, so nothing changed when trying to re-add the same ids.
This sets `reduced_evaluated_gizmo_nodes_` to `true` (probably an
oversight when this got added) so that the function returns early when
called again.
d0cf7df902