Reduce flakiness by attempting 10 times
Reduce flakiness by attempting 10 times

- DNS is flaky, and sometimes tests fail for spurious reasons
  (e.g.  <https://ci.nono.io/teams/main/pipelines/sslip.io/jobs/check-dns/builds/1621>)

fixes
```
dig: couldn't get address for 'ns-he.nono.io.': not found
  nameserver ns-he.nono.io.'s NS records match whois's ["ns-azure.nono.io.", "ns-aws.nono.io.", "ns-he.nono.io.", "ns-gce.nono.io."], `dig +short ns sslip.io @ns-he.nono.io.` (FAILED - 1)
```

cunnie/sslip.io,cunnie/sslip.io,cunnie/sslip.io,cunnie/sslip.io