flake.lock: Update

Flake lock file updates:

• Updated input 'fenix':
    'github:nix-community/fenix/1458349a1bd55105f917e962dca4b328ac0a55e8?narHash=sha256-P9VX/P2mN96MkFN8hwCYUQ%2BLV1bfH57UJ/pGwjd0Olc%3D' (2025-09-13)
  → 'github:nix-community/fenix/f4cb0863b5d772b7b378ea456ac86c359303dfa7?narHash=sha256-eU4HnBCVuBg%2Bc5UninnTh65VrbkkQ8HOjCaC3NDZLYM%3D' (2025-10-18)
• Updated input 'fenix/rust-analyzer-src':
    'github:rust-lang/rust-analyzer/9edc9cbe5d8e832b5864e09854fa94861697d2fd?narHash=sha256-/PAhxheUq4WBrW5i/JHzcCqK5fGWwLKdH6/Lu1tyS18%3D' (2025-09-08)
  → 'github:rust-lang/rust-analyzer/1e20331e42449dfc0b44bce84147a06772d045d7?narHash=sha256-WOt9KquZ1BXjMcVyHpMeliqNRL6BfRvBHFGfRDriDx4%3D' (2025-10-17)
• Updated input 'nixpkgs':
    'github:NixOS/nixpkgs/6d7ec06d6868ac6d94c371458fc2391ded9ff13d?narHash=sha256-fEvTiU4s9lWgW7mYEU/1QUPirgkn%2BodUBTaindgiziY%3D' (2025-09-13)
  → 'github:NixOS/nixpkgs/3cbe716e2346710d6e1f7c559363d14e11c32a43?narHash=sha256-J/i5K6AAz/y5dBePHQOuzC7MbhyTOKsd/GLezSbEFiM%3D' (2025-10-16)

Author: github-actions[bot]