flake.lock: Update

Flake lock file updates:

• Updated input 'crane':
    'github:ipetkov/crane/62fc1a0cbe144c1014d956e603d56bf1ffe69c7d' (2023-12-09)
  → 'github:ipetkov/crane/3330c0de31e8729bb5d01820e59ceb1640e128dc' (2023-12-16)
• Updated input 'fenix':
    'github:nix-community/fenix/aa632e1b140686853a226fa0bf85ae8ebbf72aab' (2023-12-09)
  → 'github:nix-community/fenix/8001e62f21df863304287c63f01fcc0c24c91816' (2023-12-16)
• Updated input 'fenix/rust-analyzer-src':
    'github:rust-lang/rust-analyzer/19387d3077c4c81e4a89ecec62917221fed26541' (2023-12-08)
  → 'github:rust-lang/rust-analyzer/21b06c1beb9bb59369ffd652f5d617bcf6952e05' (2023-12-15)
• Updated input 'nickel':
    'github:tweag/nickel/2819b4b28a9d1d6d4f87869a223d1914647ed8da' (2023-12-07)
  → 'github:tweag/nickel/e1113af36842a1012494342a95f76a7973495961' (2023-12-15)
• Updated input 'nixpkgs':
    'github:NixOS/nixpkgs/e9ef8a102c555da4f8f417fe5cf5bd539d8a38b7' (2023-12-08)
  → 'github:NixOS/nixpkgs/aa9d4729cbc99dabacb50e3994dcefb3ea0f7447' (2023-12-14)