[Test] Download mnist globally in CI scope
#2799
| Job | Run time |
|---|---|
| 15m 13s | |
| 5m 2s | |
| 20m 15s |
mnist globally in CI scope
#2799
| Job | Run time |
|---|---|
| 15m 13s | |
| 5m 2s | |
| 20m 15s |