Fix random test failures in ci-test jobs

gitlab-ci test jobs tend to have random failures due to the limited resources allocated to the test runners.

Part of the problem was mitigated with !1083 (f99f60a9) (which can be improved, see discussion in !1192 (merged)).

I'd like to collect here the tests that are causing random failures, so that we can address all of them

• GaudiKernel.test_StatusCodeFail
  • compilation error (g++: fatal error: Killed signal terminated program cc1plus) trying to compile GaudiKernel