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/6ffcbf59c119b0c6384c7d98f18cea06a9af7e9c?narHash=sha256-J/rtMKVUAEqOFj0ogvcHKK8HbaKhw%2BtiNrDOpEM%2BZDY%3D' (2025-10-04)
• 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/472037b789cf593172d6adf3b8d9f7a429f6cd9b?narHash=sha256-7StxDed3v2fAWLkl%2BHse9FlpjT7Dk7Cn/4vxTFyEhIg%3D' (2025-10-01)
• Updated input 'nixpkgs':
    'github:NixOS/nixpkgs/6d7ec06d6868ac6d94c371458fc2391ded9ff13d?narHash=sha256-fEvTiU4s9lWgW7mYEU/1QUPirgkn%2BodUBTaindgiziY%3D' (2025-09-13)
  → 'github:NixOS/nixpkgs/27ac93958969b5f3dccd654b402599cf3de633ac?narHash=sha256-hhM8SUI6kQMei5TImFdNQy9EDT8g2hAD161DUtbfAy0%3D' (2025-10-04)

Author: github-actions[bot]