sl pr submit --verbose does not add diagnostics

```
$ sl pr submit --verbose
pushing 1 to ssh://git@github.com/xxx/yyy
updated body for https://github.com/xxx/yyy/pull/17755
```

Exactly the same as without `--verbose`.

The context is: when I do `git push -f`, GitHub jobs are created, but when I do `sl pr submit`, jobs are not starting. Not clear who is responsible, but `sl pr submit` could provide diagnostics for investigation.