flake.lock: Update (#601)

Flake lock file updates:

• Updated input 'typelevel-nix':
    'github:typelevel/typelevel-nix/65d7a5c' (2026-04-15)
  → 'github:typelevel/typelevel-nix/fe7b1d4' (2026-05-15)
• Updated input 'typelevel-nix/nixpkgs':
    'github:nixos/nixpkgs/1304392' (2026-04-11)
  → 'github:nixos/nixpkgs/2719819' (2026-05-14)

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

Author: hnaderi