Setup xeon01 and xeon02 with slurm under nixos

On xeon01:

• Install nixos
• Setup SLURM
• Configure GRUB to boot NixOS by default

On xeon02:

• Enable serial on grub
• Install nixos
• Setup SLURM
• Configure GRUB to boot NixOS by default

On xeon07

• Setup slurmd (client server)
• Setup slurmctld (control server)