reorder system tests to shorten runtime
if tests that take a particularly long time to complete (serve-stale, dnssec, rpzrecurse) are run first, a parallel run of the system tests can finish 1-2 minutes faster.
if tests that take a particularly long time to complete (serve-stale, dnssec, rpzrecurse) are run first, a parallel run of the system tests can finish 1-2 minutes faster.