flake.lock: Update (#910)

Flake lock file updates:

• Updated input 'nixpkgs':
    'github:NixOS/nixpkgs/bffc22eb12172e6db3c5dde9e3e5628f8e3e7912?narHash=sha256-8YVQ9ZbSfuUk2bUf2KRj60NRraLPKPS0Q4QFTbc%2Bc2c%3D' (2025-01-08)
  → 'github:NixOS/nixpkgs/5df43628fdf08d642be8ba5b3625a6c70731c19c?narHash=sha256-Tbk1MZbtV2s5aG%2BiM99U8FqwxU/YNArMcWAv6clcsBc%3D' (2025-01-16)
• Updated input 'rust-overlay':
    'github:oxalica/rust-overlay/09f2869b164f8b6d5e30f0bd7ed30d6eb8237058?narHash=sha256-o%2BXYHMxGi8oiJlQ7UkDv0lzUuED6iaxZwPzD3kY7R38%3D' (2025-01-11)
  → 'github:oxalica/rust-overlay/fc839c9d5d1ebc789b4657c43c4d54838c7c01de?narHash=sha256-vlDROBAgq%2B7PEVM0vaS2zboY6DXs3oKK0qW/1dVuFs4%3D' (2025-01-18)

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