chore: update flake.lock

[mrcjkb]

Automated changes by the update-flake-lock GitHub Action.

Flake lock file updates:

• Updated input 'git-hooks':
    'github:cachix/git-hooks.nix/bca82caa46d5ec0f5d422c61fb1e30bc51313cbe?narHash=sha256-jGiy6%2BsxjNWXSjp25uoJuNfyH9zBK1PEDY0lVoL4ibQ%3D' (2026-07-02)
  → 'github:cachix/git-hooks.nix/43b3c1ab9d40fb1dbb008f451988a91e375825e9?narHash=sha256-ReRHaLgr/uVqdD8afFSn%2BmyXIfpHeOhP0yYe0TJqAA8%3D' (2026-07-17)
• Updated input 'nixpkgs':
    'github:NixOS/nixpkgs/716c7a2664ca8325617b8a7fbb609273f2c4cae7?narHash=sha256-zbcZ1dmBTPfJ7Mlqh/yLEPGpgJnwuv4Xr1xucy2WqMA%3D' (2026-07-11)
  → 'github:NixOS/nixpkgs/20535e48e12c86043b577b8518234ff5dbb26957?narHash=sha256-CdItYNdYUlm7NxqMVyQKqT2IxTwvapiPuRLWOyHTrbY%3D' (2026-07-18)

Running GitHub Actions on this PR

GitHub Actions will not run workflows on pull requests which are opened by a GitHub Action.

To run GitHub Actions workflows on this PR, run:

git branch -D update_flake_lock_action
git fetch origin
git checkout update_flake_lock_action
git commit --amend --no-edit
git push origin update_flake_lock_action --force