chore: update flake (#99)

Flake lock file updates:

• Updated input 'home-manager':
    'github:nix-community/home-manager/07c347bb50994691d7b0095f45ebd8838cf6bc38' (2023-06-27)
  → 'github:nix-community/home-manager/2a6679aa9cc3872c29ba2a57fe1b71b3e3c5649f' (2023-08-15)
• Updated input 'master':
    'github:NixOS/nixpkgs/9ea0603f8eb7a54c3219d71a2378b64402b6f8a1' (2023-08-16)
  → 'github:NixOS/nixpkgs/0b6f3e17dda02c9cf1e8edc6e411ba37093f09e2' (2023-08-20)
• Updated input 'nixos-hardware':
    'github:NixOS/nixos-hardware/430a56dd16fe583a812b2df44dca002acab2f4f6' (2023-08-12)
  → 'github:NixOS/nixos-hardware/7f1836531b126cfcf584e7d7d71bf8758bb58969' (2023-08-18)
• Updated input 'nixpkgs':
    'github:NixOS/nixpkgs/09a137528c3aea3780720d19f99cd706f52c3823' (2023-08-14)
  → 'github:NixOS/nixpkgs/4cdad15f34e6321a2f789b99d42815b9142ac2ba' (2023-08-19)
• Updated input 'nur':
    'github:nix-community/NUR/c8fd67dcbe555378765a3775a8ae811f721c7f05' (2023-08-13)
  → 'github:nix-community/NUR/18436a20915d6cc569d7fb13807a07ae5de10661' (2023-08-19)
• Updated input 'unstable':
    'github:NixOS/nixpkgs/8353344d3236d3fda429bb471c1ee008857d3b7c' (2023-08-15)
  → 'github:NixOS/nixpkgs/d680ded26da5cf104dd2735a51e88d2d8f487b4d' (2023-08-19)

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