chore(nix): Update dependencies.

Flake lock file updates:

• Updated input 'flake-parts':
    'github:hercules-ci/flake-parts/59cf3f1447cfc75087e7273b04b31e689a8599fb' (2023-08-01)
  → 'github:hercules-ci/flake-parts/7f53fdb7bdc5bb237da7fefef12d099e4fd611ca' (2023-09-01)
• Updated input 'flake-parts/nixpkgs-lib':
    'github:NixOS/nixpkgs/9e1960bc196baf6881340d53dccb203a951745a2?dir=lib' (2023-08-01)
  → 'github:NixOS/nixpkgs/3e52e76b70d5508f3cec70b882a29199f4d1ee85?dir=lib' (2023-08-31)
• Updated input 'gitignore':
    'github:hercules-ci/gitignore.nix/a20de23b925fd8264fd7fad6454652e142fd7f73' (2022-08-14)
  → 'github:hercules-ci/gitignore.nix/9e21c80adf67ebcb077d75bd5e7d724d21eeafd6' (2023-09-07)
• Updated input 'hacknix':
    'github:hackworthltd/hacknix/7d0d518171938c2b95f7cb8da58f291f5ed22f30' (2023-07-30)
  → 'github:hackworthltd/hacknix/3764c7430b8c3ea7c64f5b82eca4462572d4d414' (2023-09-22)
• Updated input 'hacknix/flake-parts':
    'github:hercules-ci/flake-parts/8e8d955c22df93dbe24f19ea04f47a74adbdc5ec' (2023-07-04)
  → 'github:hercules-ci/flake-parts/7f53fdb7bdc5bb237da7fefef12d099e4fd611ca' (2023-09-01)
• Updated input 'hacknix/flake-parts/nixpkgs-lib':
    'github:NixOS/nixpkgs/4bc72cae107788bf3f24f30db2e2f685c9298dc9?dir=lib' (2023-06-29)
  → 'github:NixOS/nixpkgs/3e52e76b70d5508f3cec70b882a29199f4d1ee85?dir=lib' (2023-08-31)
• Updated input 'hacknix/gitignore-nix':
    'github:hercules-ci/gitignore.nix/a20de23b925fd8264fd7fad6454652e142fd7f73' (2022-08-14)
  → 'github:hercules-ci/gitignore.nix/9e21c80adf67ebcb077d75bd5e7d724d21eeafd6' (2023-09-07)
• Updated input 'hacknix/nix-darwin':
    'github:LnL7/nix-darwin/16c07487ac9bc59f58b121d13160c67befa3342e' (2023-07-27)
  → 'github:LnL7/nix-darwin/afeddc412b3a3b0e7c9ef7ea5fbdf2186781d102' (2023-09-19)
• Updated input 'hacknix/nixos-generators':
    'github:nix-community/nixos-generators/b1171de4d362c022130c92d7c8adc4bf2b83d586' (2023-07-23)
  → 'github:nix-community/nixos-generators/8ee78470029e641cddbd8721496da1316b47d3b4' (2023-09-04)
• Updated input 'hacknix/nixos-generators/nixlib':
    'github:nix-community/nixpkgs.lib/02fea408f27186f139153e1ae88f8ab2abd9c22c' (2023-07-16)
  → 'github:nix-community/nixpkgs.lib/f5af57d3ef9947a70ac86e42695231ac1ad00c25' (2023-09-03)
• Updated input 'hacknix/nixpkgs':
    'github:NixOS/nixpkgs/f68a459f743733d53a0f5f9ce4b7b70eea5f8722' (2023-07-28)
  → 'github:NixOS/nixpkgs/fe977679240ac2027b151ecca1bc6ce808c2e8af' (2023-09-20)
• Updated input 'hacknix/pre-commit-hooks-nix':
    'github:cachix/pre-commit-hooks.nix/9289996dcac62fd45836db7c07b87d2521eb526d' (2023-07-27)
  → 'github:cachix/pre-commit-hooks.nix/4f883a76282bc28eb952570afc3d8a1bf6f481d7' (2023-09-10)
• Updated input 'pre-commit-hooks-nix':
    'github:cachix/pre-commit-hooks.nix/ebb43bdacd1af8954d04869c77bc3b61fde515e4' (2023-08-03)
  → 'github:cachix/pre-commit-hooks.nix/4f883a76282bc28eb952570afc3d8a1bf6f481d7' (2023-09-10)
• Updated input 'treefmt-nix':
    'github:numtide/treefmt-nix/fab56c8ce88f593300cd8c7351c9f97d10c333c5' (2023-08-01)
  → 'github:numtide/treefmt-nix/e951529be2e7c669487de78f5aef8597bbae5fca' (2023-09-21)