Grant access to metricsdb-03 to metrics team and setup basic install

in #42215 (closed) the new machine that was donated was installed in the datacenter and then had its OS installed on it.

fwiw the machine has about 760Gb of ram and a 28Tb disk array for data. the "system" disk also has a capacity of 1.7Tb and there's also still one 3.6Tb disk unused (since it's the only one of that size)

currently we have not setup ssh access / sudo access for it for non-TPA members.

@hiro the new machine for the metrics team is now ready and we just need to know how to setup access, depending on how that machine is bound to get used and who's bound to be responsible for what in it. could you share, when ready for it, some information about the plan regarding this machine?

/cc @anarcat