feat: update flake.lock (#67)

Flake lock file updates:

• Updated input 'nixpkgs':
    'github:nixos/nixpkgs/825479c345a7f806485b7f00dbe3abb50641b083?narHash=sha256-nU6AezEX4EuahTO1YopzueAXfjFfmCHylYEFCagduHU%3D' (2025-01-24)
  → 'github:nixos/nixpkgs/3a228057f5b619feb3186e986dbe76278d707b6e?narHash=sha256-xvTo0Aw0%2Bveek7hvEVLzErmJyQkEcRk6PSR4zsRQFEc%3D' (2025-02-01)

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Author: github-actions[bot]