feat: update flake.lock (#95)

Flake lock file updates:

• Updated input 'nixpkgs':
    'github:nixos/nixpkgs/c2ae88e026f9525daf89587f3cbee584b92b6134?narHash=sha256-erbiH2agUTD0Z30xcVSFcDHzkRvkRXOQ3lb887bcVrs%3D' (2025-08-06)
  → 'github:nixos/nixpkgs/fbcf476f790d8a217c3eab4e12033dc4a0f6d23c?narHash=sha256-wNO3%2BKs2jZJ4nTHMuks%2BcxAiVBGNuEBXsT29Bz6HASo%3D' (2025-08-14)

Co-authored-by: github-actions[bot] <github-actions[bot]@users.noreply.github.com>

Author: github-actions[bot]