flake.lock: Update

Flake lock file updates:

• Updated input 'typelevel-nix':
    'github:typelevel/typelevel-nix/7439a681d52a7e7ed344b6301e6f8d5bb4ec582a' (2023-07-31)
  → 'github:typelevel/typelevel-nix/ed9f189d304aa85cb74c052d063dfc11023b4f33' (2023-08-21)
• Updated input 'typelevel-nix/devshell':
    'github:numtide/devshell/f9238ec3d75cefbb2b42a44948c4e8fb1ae9a205' (2023-07-03)
  → 'github:numtide/devshell/d208c58e2f7afef838add5f18a9936b12a71d695' (2023-08-20)
• Updated input 'typelevel-nix/nixpkgs':
    'github:nixos/nixpkgs/3acb5c4264c490e7714d503c7166a3fde0c51324' (2023-07-30)
  → 'github:nixos/nixpkgs/3476a10478587dec90acb14ec6bde0966c545cc0' (2023-08-20)