Dunder del in configsession was modified with a conditional for use with vyconf: the vyconf case uses a finalizer; the legacy case was left untouched. However, the conditional itself is improper for del, wherein garbage collection may have already removed access to the import (strictly speaking, the legacy construction is improper for del). Although this does not affect rolling under bookworm, it is caught under trixie's later Python version. Extend the proper use of finalizers to the legacy case.