Configure TRIM for SSDs to prevent wearing in all nodes

Currently we don't have any TRIM enabled in any nodes. Not the discard mount option (continuous TRIM):

hut% findmnt /
TARGET
  SOURCE                   FSTYPE OPTIONS
/ /dev/disk/by-label/nixos ext4   rw,relatime

And the fstrim service is not enabled.

hut% nix eval .#nixosConfigurations.hut.config.services.fstrim.enable
false