Broken link check build fails

See build https://github.com/exasol/error-reporting-lua/runs/8174259210?check_suite_focus=true

```
 ERROR: 2 dead links found!
[✖] http://olivinelabs.com/busted/ → Status: 404
[✖] https://keplerproject.github.io/luacov/ → Status: 404
```