exekall.engine: Remove handling of a case that can never happen
exekall.engine: Remove handling of a case that can never happen

Only produced classes end up in cls_map by construction, so we will always have
an operator to produce them.

credp/lisa,credp/lisa,ARM-software/lisa,ARM-software/lisa,credp/lisa,ARM-software/lisa,credp/lisa,ARM-software/lisa