Threading Wait on Timer tests failing on Linux CI

[JoelLinn]

Describe what's going wrong

Drone CI sporadically fails on "Wait on Timer" test. https://github.com/xenia-project/xenia/blob/500bbe9e0d69e4c62bef0e81b3aa4097c09503f5/src/xenia/base/testing/threading_test.cc#L783 This is likely to huge overprovision of the CI servers and the test thread not getting woken up fast enough as desired after it has entered sleep

Describe what should happen

It shouldn't fail lol. Hopefully this will get better once the linux threading also uses the new timer code and is reworked.

[JoelLinn]

Also affects "Wait on Multiple Timers" test