flake.lock: Update

Flake lock file updates:

• Updated input 'crane':
    'github:ipetkov/crane/9fa361a' (2025-01-04)
  → 'github:ipetkov/crane/69f538c' (2025-12-07)
• Updated input 'nixpkgs':
    'github:NixOS/nixpkgs/a278711' (2025-01-03)
  → 'github:NixOS/nixpkgs/f997fa0' (2025-12-11)
• Updated input 'rust-overlay':
    'github:oxalica/rust-overlay/d40e15e' (2025-01-04)
  → 'github:oxalica/rust-overlay/348b94e' (2025-12-13)

Author: github-actions[bot]