fmt/temporal: fix parsing of spans like PT843517081h
#335
| Job | Run time |
|---|---|
| 1m 18s | |
| 6s | |
| 1m 31s | |
| 1m 51s | |
| 7m 11s | |
| 2m 13s | |
| 7m 43s | |
| 1m 11s | |
| 19s | |
| 2m 37s | |
| 5m 43s | |
| 7m 51s | |
| 2m 11s | |
| 2m 1s | |
| 6m 14s | |
| 2m 15s | |
| 8m 9s | |
| 1h 0m 24s |