Installability upgrade/downgrade tests fail when previous version of package is broken

https://src.fedoraproject.org/rpms/octave/pull-request/11 was submitted by a user to prompt a rebuild of octave in Rawhide, because it had become uninstallable due to an updated sundials package that brought new library versions.

The new build was actually fine, but the installability tests showed as Failing because it wasn't able to upgrade from or downgrade to the previous version.

Considering the previous version was known to be broken (the entire reason the PR was submitted in the first place), that seems like a misleading sort of failure. Fortunately I took the time to dig into the test logs and determine that it was a false negative, rather than just declining to merge the PR on the basis of "failing" tests.