flake.lock: Update

Flake lock file updates:

• Updated input 'base16-vim':
    'github:tinted-theming/base16-vim/257d0d2aa78a41f5297620ce55268b8ab173c8d2' (2024-02-28)
  → 'github:tinted-theming/base16-vim/a0a8b65d4e2f7d9173ede86280d0528159336257' (2024-03-28)
• Updated input 'nix-index-database':
    'github:nix-community/nix-index-database/e25efda85e39fcdc845e371971ac4384989c4295' (2024-03-17)
  → 'github:nix-community/nix-index-database/34519f3bb678a5abbddf7b200ac5347263ee781b' (2024-03-24)
• Updated input 'nixos-hardware':
    'github:nixos/nixos-hardware/1e679b9a9970780cd5d4dfe755a74a8f96d33388' (2024-03-18)
  → 'github:nixos/nixos-hardware/9a763a7acc4cfbb8603bb0231fec3eda864f81c0' (2024-03-25)
• Updated input 'nixpkgs':
    'github:nixos/nixpkgs/56528ee42526794d413d6f244648aaee4a7b56c0' (2024-03-22)
  → 'github:nixos/nixpkgs/219951b495fc2eac67b1456824cc1ec1fd2ee659' (2024-03-28)
• Updated input 'nixpkgs-unstable':
    'github:nixos/nixpkgs/20f77aa09916374aa3141cbc605c955626762c9a' (2024-03-21)
  → 'github:nixos/nixpkgs/d8fe5e6c92d0d190646fb9f1056741a229980089' (2024-03-29)
• Updated input 'nur':
    'github:nix-community/NUR/1393242e65123b8752087e0f997626071e1f8656' (2024-03-24)
  → 'github:nix-community/NUR/7d8717afcc55c8c2bb1a35d4be118e731f99be2f' (2024-03-30)
• Updated input 'sops-nix':
    'github:Mic92/sops-nix/83b68a0e8c94b72cdd0a6e547a14ca7eb1c03616' (2024-03-17)
  → 'github:Mic92/sops-nix/405987a66cce9a4a82f321f11b205982a7127c88' (2024-03-24)
• Updated input 'tt-schemes':
    'github:tinted-theming/schemes/ae4ce8b0d1f9b247d3add88a23aec3d833ae76d1' (2024-02-11)
  → 'github:tinted-theming/schemes/45f3d879fb64276df7e69c18f7adbb88938e10e7' (2024-03-28)