flake.lock: Update

Flake lock file updates:

• Updated input 'nixpkgs':
    'github:nixos/nixpkgs/ae5c332cbb5827f6b1f02572496b141021de335f' (2024-01-25)
  → 'github:nixos/nixpkgs/b8b232ae7b8b144397fdb12d20f592e5e7c1a64d' (2024-01-31)
• Updated input 'rust-overlay':
    'github:oxalica/rust-overlay/ca8b329ae48f3c760f0e7e0249e8afa50edc8ed1' (2024-01-28)
  → 'github:oxalica/rust-overlay/130b1b89799ae76c0ad1bf4b9019470403d9fbe1' (2024-02-03)
• Updated input 'rust-overlay/flake-utils':
    'github:numtide/flake-utils/cfacdce06f30d2b68473a46042957675eebb3401' (2023-04-11)
  → 'github:numtide/flake-utils/1ef2e671c3b0c19053962c07dbda38332dcebf26' (2024-01-15)