flake.lock: Update (#444)

Flake lock file updates:

• Updated input 'CHaP':
    'github:input-output-hk/cardano-haskell-packages/5726d16ea0f440f705594bef95adbc6bdbf7778b' (2023-08-11)
  → 'github:input-output-hk/cardano-haskell-packages/e4ecf31ea5a805eb9fc07a4247e8e25eeb2738e9' (2023-08-18)
• Updated input 'hackage-nix':
    'github:input-output-hk/hackage.nix/d7987285bee6a905d4884c7cfca38c917f551abf' (2023-08-12)
  → 'github:input-output-hk/hackage.nix/f1e90fd26b31b4f525cd10565fe8429b134dd335' (2023-08-19)

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