Add some missing Optional type annotations to interval_range and `r…
#3366
| Job | Run time |
|---|---|
| 4m 25s | |
| 4m 31s | |
| 4m 30s | |
| 16s | |
| 7m 30s | |
| 7m 51s | |
| 4m 31s | |
| 5m 20s | |
| 2m 27s | |
| 4m 1s | |
| 3m 25s | |
| 5m 38s | |
| 3m 50s | |
| 58m 15s |