build: bump dnsruby from 1.61.2 to 1.61.3 in /docs

Bumps [dnsruby](https://github.com/alexdalitz/dnsruby) from 1.61.2 to 1.61.3.
- [Release notes](https://github.com/alexdalitz/dnsruby/releases)
- [Changelog](https://github.com/alexdalitz/dnsruby/blob/master/RELEASE_NOTES.md)
- [Commits](https://github.com/alexdalitz/dnsruby/commits

)

Signed-off-by: dependabot-preview[bot] <support@dependabot.com>