flake.lock: Update (#437)

Flake lock file updates:

• Updated input 'CHaP':
    'github:input-output-hk/cardano-haskell-packages/3615dfca0ee10cb5e66f0524725c4c775a2b7f83' (2023-08-04)
  → 'github:input-output-hk/cardano-haskell-packages/5726d16ea0f440f705594bef95adbc6bdbf7778b' (2023-08-11)
• Updated input 'hackage-nix':
    'github:input-output-hk/hackage.nix/4dcf5a4a045945aa55c1f2be9d2dadce968488fa' (2023-08-05)
  → 'github:input-output-hk/hackage.nix/d7987285bee6a905d4884c7cfca38c917f551abf' (2023-08-12)

Co-authored-by: github-actions[bot] <github-actions[bot]@users.noreply.github.com>
Co-authored-by: Michael Peyton Jones <me@michaelpj.com>