flake.lock: Update

Flake lock file updates:

• Updated input 'nixpkgs':
    'https://api.flakehub.com/f/pinned/NixOS/nixpkgs/0.1.533189%2Brev-87828a0e03d1418e848d3dd3f3014a632e4a4f64/018b0dc8-e84f-7c59-b5d6-16849c3b2074/source.tar.gz?narHash=sha256-YXUNI0kLEcI5g8lqGMb0nh67fY9f2YoJsILafh6zlMo%3D' (2023-10-06)
  → 'https://api.flakehub.com/f/pinned/NixOS/nixpkgs/0.1.614481%2Brev-5c24cf2f0a12ad855f444c30b2421d044120c66f/018efa00-a443-7f41-b371-ce568b5c7e9f/source.tar.gz?narHash=sha256-XtTSSIB2DA6tOv%2Bl0FhvfDMiyCmhoRbNB%2B0SeInZkbk%3D' (2024-04-19)