CI: Intermittent failure in sched_yield test

https://buildkite.com/julialang/rr/builds/288#f90ad74f-115a-4ee1-842d-a46cb07ca9a6

1180/2773 Test  #586: sched_yield .......................................................***Failed  Error regular expression found in output. Regex=[FAILED]  0.47 sec
--
  | source_dir/src/test/util.sh: line 245: 115914 Aborted                 _RR_TRACE_DIR="$workdir" test-monitor $TIMEOUT record.err $RR_EXE $GLOBAL_OPTIONS record $LIB_ARG $RECORD_ARGS "$exe" $exeargs > record.out 2> record.err
  | Test 'sched_yield' FAILED: : token 'EXIT-SUCCESS' not in record.out:
  | --------------------------------------------------
  | FAILED: errno=0 (Success)
  | FAILED: !("ping thread: " && PONG == last)
  | --------------------------------------------------
  | Test sched_yield failed, leaving behind /cache/build/exclusive-amdci3-0/julialang/rr/obj/my_temp_parent_dir/jl_uDNbtn/rr-test-sched_yield-ce1R7Q0DP
  | To replay the failed test, run
  | _RR_TRACE_DIR=/cache/build/exclusive-amdci3-0/julialang/rr/obj/my_temp_parent_dir/jl_uDNbtn/rr-test-sched_yield-ce1R7Q0DP rr replay
  |  

Start with the sched_yield test failure in the Buildkite log and source_dir/src/test/util.sh:245. Use the provided RR_TRACE_DIR replay command to inspect the failed trace and determine why EXIT-SUCCESS is missing. Done means the test completes without FAILED output and reliably reports EXIT-SUCCESS.