reduce test load when logging

I suspect some test which scale whith the number of CPUs to timeout mostly on jenkins2. This patch reduces the load when logging is active and increases the load when logging is off. Therefore our test build with debugoptimized will do less and hopefully only timeout when they actually hung and the release test will do more.

Exaple: https://gitlab.cs.fau.de/i4/manycore/emper/-/jobs/481023
Both SimpleActor and AlarmActor tests take more than 120 seconds.