If true (the default), calling SortSystems() will sort the system update list, respecting the constraints imposed by [UpdateBefore] and [UpdateAfter] attributes.
SortSystems() is called automatically during
DefaultWorldInitialization, as well as at the beginning of ComponentSystemGroup.OnUpdate(), but may also be
called manually.
If false, calls to SortSystems() on this system group will have no effect on update order of systems in this
group (though SortSystems() will still be called recursively on any child system groups). The group's systems
will update in the order of the most recent sort operation, with any newly-added systems updating in
insertion order at the end of the list.
Setting this value to false is not recommended unless you know exactly what you're doing, and you have full
control over the systems which will be updated in this group.