feat: update flake.lock (#65)

Flake lock file updates:

• Updated input 'nixpkgs':
    'github:nixos/nixpkgs/bffc22eb12172e6db3c5dde9e3e5628f8e3e7912?narHash=sha256-8YVQ9ZbSfuUk2bUf2KRj60NRraLPKPS0Q4QFTbc%2Bc2c%3D' (2025-01-08)
  → 'github:nixos/nixpkgs/5df43628fdf08d642be8ba5b3625a6c70731c19c?narHash=sha256-Tbk1MZbtV2s5aG%2BiM99U8FqwxU/YNArMcWAv6clcsBc%3D' (2025-01-16)

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Author: github-actions[bot]