This avoids assuming that `BKE_ntree_update_main` has run on a node tree before
the depsgraph is build. The update code already finds the dependencies to
determine if a relations update is necessary or not. To avoid detecting these
dependencies again (which requires iterating over all the nested nodes), they
were cached on the node group so that they can be used when the depsgraph is
build.
However, since the update code does not run in all necessary cases yet
(#131598), this does not work currently. This patch fixes the situation by
removing the optimization of not having to find all dependencies again when the
depsgraph is build.
This optimization can be introduced again after we can be more sure that the
node tree update code runs whenever the node tree changes (which is what #131665
tries, but requires more discussion).
Pull Request: https://projects.blender.org/blender/blender/pulls/131685
53ea147a51