nix: update flake.lock

Flake lock file updates:

• Updated input 'bootspec-secureboot':
    'github:DeterminateSystems/bootspec-secureboot/513215a59fee38006f9fb3fa65deff595e5bbbdc' (2023-06-16)
  → 'github:DeterminateSystems/bootspec-secureboot/cff36b9eff8b4cc4abe77c87ad2eedb9919b6cd5' (2023-07-27)
• Updated input 'darwin':
    'github:LnL7/nix-darwin/efd35d99ce412335c478dff9da9a4256bbd39757' (2023-07-25)
  → 'github:LnL7/nix-darwin/16c07487ac9bc59f58b121d13160c67befa3342e' (2023-07-27)
• Updated input 'home-manager':
    'github:nix-community/home-manager/d309a62ee81faec56dd31a263a0184b0e3227e36' (2023-07-24)
  → 'github:nix-community/home-manager/4fd794d3df88735dcf9662155d77b08a2e2dde29' (2023-07-31)
• Updated input 'impermanence':
    'github:nix-community/impermanence/89253fb1518063556edd5e54509c30ac3089d5e6' (2023-05-16)
  → 'github:nix-community/impermanence/e3a7acd113903269a1b5c8b527e84ce7ee859851' (2023-07-31)
• Updated input 'nix-index-database':
    'github:Mic92/nix-index-database/c1e6fc40dd5c0d16940bc012421268b94e404b0b' (2023-07-23)
  → 'github:Mic92/nix-index-database/d74b8171153ae35d7d323a9b1ad6c4cf7a995591' (2023-07-30)
• Updated input 'nixos-hardware':
    'github:NixOS/nixos-hardware/ba9650b14e83b365fb9e731f7d7c803f22d2aecf' (2023-07-24)
  → 'github:NixOS/nixos-hardware/96e5a0a0e8568c998135ea05575a9ed2c87f5492' (2023-07-30)
• Updated input 'nixpkgs':
    'github:NixOS/nixpkgs/b12803b6d90e2e583429bb79b859ca53c348b39a' (2023-07-24)
  → 'github:NixOS/nixpkgs/fb942492b7accdee4e6d17f5447091c65897dde4' (2023-07-31)