Update Ubuntu version of citest

[nook24]

This PR updates the used version of Ubuntu from 20.04 to 22.04 to resolve the current build issue:
https://github.com/naemon/naemon.github.io/actions/runs/9538466238/job/26612339906#step:3:1038

 Resolving dependencies....
ffi-1.17.0-x86_64-linux-musl requires rubygems version >= 3.3.22, which is
incompatible with the current version, 3.1.2

The sudo in front of bundle install is fixing

Retrying download gem from https://rubygems.org/ due to error (2/4): Bundler::PermissionError There was an error while trying to write to `/var/lib/gems/3.2.0/cache/connection_pool-2.4.1.gem`. It is likely that you need to grant write permissions for that path.

this error.

[sni]

looks good, thanks