fix: properly locate OS-installed system Ruby
#549
| Job | Run time |
|---|---|
| 4m 17s | |
| 4m 0s | |
| 3m 17s | |
| 4m 11s | |
| 4m 26s | |
| 5m 33s | |
| 5m 35s | |
| 6m 4s | |
| 4m 41s | |
| 4m 58s | |
| 4m 29s | |
| 8m 13s | |
| 6m 33s | |
| 4m 49s | |
| 4m 36s | |
| 4m 57s | |
| 5m 4s | |
| 8m 57s | |
| 10m 48s | |
| 4m 45s | |
| 4m 51s | |
| 2m 33s | |
| 2m 23s | |
| 2m 56s | |
| 3m 19s | |
| 4m 30s | |
| 1m 59s | |
| 1m 48s | |
| 2m 32s | |
| 2m 46s | |
| 34s | |
| 32s | |
| 1m 9s | |
| 57s | |
| 5m 5s | |
| 5m 8s | |
| 0s | |
| 2h 33m 15s |