flake.lock: Update

Flake lock file updates:

• Updated input 'fenix':
    'github:nix-community/fenix/25db7a6f4de7dea678620785e03fbc4560c00672?narHash=sha256-wC9PR%2BrPjmcpnPdOIDwyNwQiRhNsuDs3oZY3t42f4uA%3D' (2025-07-26)
  → 'github:nix-community/fenix/f4cb0863b5d772b7b378ea456ac86c359303dfa7?narHash=sha256-eU4HnBCVuBg%2Bc5UninnTh65VrbkkQ8HOjCaC3NDZLYM%3D' (2025-10-18)
• Updated input 'fenix/rust-analyzer-src':
    'github:rust-lang/rust-analyzer/51e77c9d7b9b99f7a230bf5179ef1343befd71ac?narHash=sha256-5XbVpJwiy%2Bsw1v4PXSAz4lgJnVna6xkzqyZtoHymFJA%3D' (2025-07-25)
  → 'github:rust-lang/rust-analyzer/1e20331e42449dfc0b44bce84147a06772d045d7?narHash=sha256-WOt9KquZ1BXjMcVyHpMeliqNRL6BfRvBHFGfRDriDx4%3D' (2025-10-17)
• Updated input 'nixpkgs':
    'github:NixOS/nixpkgs/6027c30c8e9810896b92429f0092f624f7b1aace?narHash=sha256-cnL5WWn/xkZoyH/03NNUS7QgW5vI7D1i74g48qplCvg%3D' (2025-07-25)
  → 'github:NixOS/nixpkgs/3cbe716e2346710d6e1f7c559363d14e11c32a43?narHash=sha256-J/i5K6AAz/y5dBePHQOuzC7MbhyTOKsd/GLezSbEFiM%3D' (2025-10-16)

Author: github-actions[bot]