By: Tom Sydney Kerckhove <syd@cs-syd.eu>
Fix file locking: use withSystemTempFile with useHandleOpen for both stdout and stderr
| Time to Start | Worker time | Duration | Time to finish | Idle | |
| Config | 0s | 6s | 6s | 6s | 0s |
| Eval | 6s | 2m33s | 2m33s | 2m40s | 0s |
| Build | 1m21s | 9m53s | - | - | 0s |
| Suite | 0s | 12m33s | - | - | 5h30m55s |