staging: Realign service urls documented and the associated services in dynamic infrastructure

This went ouf of sync during the migrations to service in the dynamic infrastructure [1]. The focus was to migrate the services and the synchronization with the documentation slowly got out of date during the process.

The goal is thus to expose again the services mentioned as accessible per the documentation. Some dns names and ingress services will need to be adapted accordingly for the access to be opened again. As a result the documentation will end up being updated apropriately too.

Missing icinga probes will be installed on those missing endpoints too.

• Expose services to the vpn that were already mentioned as such
• Add icinga probes around it (so we get notified if one of them changes)
• swh/devel/swh-docs!404 (merged): Report documentation changes
• Decommission objstorage0.staging for the benefit of objstorage-ro.staging (dynamic instance)

[1] https://docs.softwareheritage.org/sysadm/network-architecture/service-urls.html#internal-services