tests: Skip 'reraise sigfpe' test when triggering SIGFPE doesn't work.
Also only run the 'baseline sigfpe' on architectures that are known to work. This still enforces testing on some known working architectures without having to know all working and non-working architectures beforehand.
tests: Skip reraise sigfpe on s390x for now. It fails in autopkgtest and stops migration into testing, which also blocks tuiwidgets from initial testing migration.
