GHA: use nightly toolchain directly in coverage CI job
#4621
| Job | Run time |
|---|---|
| 2m 48s | |
| 2m 40s | |
| 5m 45s | |
| 2m 45s | |
| 2m 41s | |
| 2m 52s | |
| 10m 48s | |
| 39s | |
| 1m 47s | |
| 4m 38s | |
| 16s | |
| 4m 33s | |
| 8m 9s | |
| 12m 31s | |
| 10m 4s | |
| 6m 36s | |
| 4m 42s | |
| 1h 24m 14s |