flake.lock: Update (#857)

Flake lock file updates:

• Updated input 'nixpkgs':
    'github:NixOS/nixpkgs/5d67ea6b4b63378b9c13be21e2ec9d1afc921713?narHash=sha256-Pj39hSoUA86ZePPF/UXiYHHM7hMIkios8TYG29kQT4g%3D' (2024-12-11)
  → 'github:NixOS/nixpkgs/d3c42f187194c26d9f0309a8ecc469d6c878ce33?narHash=sha256-cHar1vqHOOyC7f1%2BtVycPoWTfKIaqkoe1Q6TnKzuti4%3D' (2024-12-17)
• Updated input 'rust-overlay':
    'github:oxalica/rust-overlay/81fe5c27cb281a9b796d7ad05ad9179e5bd0c78d?narHash=sha256-1%2Br8wYucn8kp9d/IBW1uYGs31QQmSZURElsiOTx65xM%3D' (2024-12-14)
  → 'github:oxalica/rust-overlay/f9086701f5f3d36b8e5f4a3b9c93579ebc2581e6?narHash=sha256-0DUuObdcPITVOMMymq2y6YlM%2B%2BQEWXZO3cTm6RGYgL8%3D' (2024-12-21)

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