flake.lock: Update

Flake lock file updates:

• Updated input 'flake-utils':
    'github:numtide/flake-utils/ff7b65b44d01cf9ba6a71320833626af21126384' (2023-09-12)
  → 'github:numtide/flake-utils/1ef2e671c3b0c19053962c07dbda38332dcebf26' (2024-01-15)
• Updated input 'nixpkgs':
    'github:NixOS/nixpkgs/85f1ba3e51676fa8cc604a3d863d729026a6b8eb' (2023-11-04)
  → 'github:NixOS/nixpkgs/a4d4fe8c5002202493e87ec8dbc91335ff55552c' (2024-02-15)
• Updated input 'poetry2nix':
    'github:nix-community/poetry2nix/bf0601d5d9ae7334fa80f5f7c9648009390046ca' (2023-11-07)
  → 'github:nix-community/poetry2nix/d04d053c3c032083ec088a5870f3a4ca50e26706' (2024-02-16)
• Updated input 'poetry2nix/treefmt-nix':
    'github:numtide/treefmt-nix/5deb8dc125a9f83b65ca86cf0c8167c46593e0b1' (2023-10-27)
  → 'github:numtide/treefmt-nix/e82f32aa7f06bbbd56d7b12186d555223dc399d1' (2023-11-12)