`dora grid ... -t 0` crashes if the job hasn't logged anything yet

## 🐛 Bug Report
When I run `dora grid` with the `-t` parameter to monitor the logs, the command stops if the job has not logged anything (e.g. it's still pending).
It might be worth to continue monitoring even when the log does not exists yet.
```
$ dora grid my_grid -t 0
WARNING: Log .../dora_outputs/xps/d3843038/latest/61700001_0_log.out does not exist
```