labs: Centralize config of which projects have NFS enabled
- A config file that is the canonical source of truth about which projects have which NFS mounts enabled.
- A puppet function (nfs_volume_mounted) which can be called to check if a particular volume should be mounted in a particular project.
This replaces the current setup, where the data is contained in
LDAP (set via 'configure' in wikitech) and in hiera (to set
which volumes puppet will actually try to mount).
This also will introduce policy changes:
- New projects will not get NFS by default anymore
- Opting into NFS requires that the project owner pokes someone from the Ops team and explains their rationale. This should be reflected in the instructions for requesting a new project at T76375
Follow up changes:
- Update manage-nfs-volumes deamon to read from this config file than from LDAP
- Continue auditing projects, removing NFS when not needed (See T102240)