Infrastructure: silence RAID controller cache/BBU monitoring for machines that
do not have a BBU (#PL-126095).
Nginx: generate dhparams at /var/lib/dhparams/nginx.pem.
Note they are not used by default and must be added to the config manually or
by setting services.nginx.sslDhparam = config.security.dhparams.params.nginx.path;
(#-PL-129859).