Update nixpkgs.

Weekly kernel update. 🙃 It looks like there are also bind (i.e. /bin/host) and samba (dependency of zfs-user) updates.

nix store diff-closures

VirtualBox-GuestAdditions: 6.1.30-5.10.94 → 6.1.30-5.10.96
bind: 9.16.16 → 9.16.25
cpupower: 5.10.94 → 5.10.96
ena: 2.5.0-5.10.94 → 2.5.0-5.10.96
initrd-linux: 5.10.94 → 5.10.96, -136.3 KiB
linux: 5.10.94, 5.10.94-modules → 5.10.96, 5.10.96-modules, +20.8 KiB
nixos-system-monitoring: 21.11.335665.0f316e4d72d → 21.11.335820.521e4d7d13b
nixos-system-payments: 21.11.335665.0f316e4d72d → 21.11.335820.521e4d7d13b
nixos-system-storage001: 21.11.335665.0f316e4d72d → 21.11.335820.521e4d7d13b
nixos-system-storage002: 21.11.335665.0f316e4d72d → 21.11.335820.521e4d7d13b
nixos-system-storage003: 21.11.335665.0f316e4d72d → 21.11.335820.521e4d7d13b
nixos-system-storage004: 21.11.335665.0f316e4d72d → 21.11.335820.521e4d7d13b
nixos-system-storage005: 21.11.335665.0f316e4d72d → 21.11.335820.521e4d7d13b
nixos-system-storage1: 21.11.335665.0f316e4d72d → 21.11.335820.521e4d7d13b
nixos-system-storage2: 21.11.335665.0f316e4d72d → 21.11.335820.521e4d7d13b
samba: 4.15.3 → 4.15.5
stage: +19.4 KiB
zfs-kernel: 2.1.2-5.10.94 → 2.1.2-5.10.96