Improve `PROJECT_ROOT` discovery (#167) - only set it before commands that require it - don’t attempt to set it if it’s already set
| Time to Start | Worker time | Duration | Time to finish | |
| Config | 0s | 1s | 1s | 2s |
| Eval | 3s | 34s | 34s | 37s |
| Build | 37s | 2m18s | 2m43s | 3m21s |
| Suite | 0s | 2m54s | 3m20s | 3m21s |