Switch build-image-variants to a self-hosted runner
#44
| Job | Run time |
|---|---|
| 4m 10s | |
| 51m 27s | |
| 2h 35m 0s | |
| 49m 32s | |
| 52m 18s | |
| 1h 17m 22s | |
| 2h 13m 16s | |
| 1h 26m 42s | |
| 5h 59m 43s | |
| 2h 45m 44s | |
| 17m 39s | |
| 19m 22s | |
| 17m 42s | |
| 18m 47s | |
| 16m 47s | |
| 20h 25m 31s |