flake.lock: Update (#47)

Flake lock file updates:

• Updated input 'nixpkgs':
    'github:NixOS/nixpkgs/3e41b24abd260e8f71dbe2f5737d24122f972158?narHash=sha256-rxO%2Buc/KFbSJp%2BpgyXRuAX6QlG9hJdnt0BXpEQRXY%2BU%3D' (2026-06-16)
  → 'github:NixOS/nixpkgs/89570f24e97e614aa34aa9ab1c927b6578a43775?narHash=sha256-EMzXKmnOtBQ2MnvpiNOm7E%2BkOMvdPrIKaeg52Tip2Uk%3D' (2026-06-23)

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

Author: mrcjkb