nix: update flake.lock (#219)

Flake lock file updates:

• Updated input 'nixpkgs':
    'github:NixOS/nixpkgs/733453ac54a40997a6a690b60f3942d79560247c?narHash=sha256-Hwm46lggqtihMaRuxbNaC1ACcU2a0jO/HXqrdjMatXk%3D' (2024-07-26)
  → 'github:NixOS/nixpkgs/5de1564aed415bf9d0f281461babc2d101dd49ff?narHash=sha256-Nf/iQWamRVAwAPFccQMfm5Qcf%2BrLLnU1rWG3f9orDVE%3D' (2024-08-22)
• Updated input 'treefmt-nix':
    'github:numtide/treefmt-nix/8db8970be1fb8be9c845af7ebec53b699fe7e009?narHash=sha256-6Pqa0bi5nV74IZcENKYRToRNM5obo1EQ%2B3ihtunJ014%3D' (2024-07-23)
  → 'github:numtide/treefmt-nix/070f834771efa715f3e74cd8ab93ecc96fabc951?narHash=sha256-kKJtaiU5Ou%2Be/0Qs7SICXF22DLx4V/WhG1P6%2Bk4yeOE%3D' (2024-08-22)

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