include missing |None in concat and read_table stubs
#3372
| Job | Run time |
|---|---|
| 14s | |
| 4m 24s | |
| 4m 7s | |
| 5m 44s | |
| 3m 47s | |
| 4m 21s | |
| 6m 55s | |
| 4m 31s | |
| 7m 16s | |
| 3m 39s | |
| 3m 36s | |
| 4m 9s | |
| 6m 35s | |
| 59m 18s |