flake.lock: Update

Flake lock file updates:

• Updated input 'fenix':
    'github:nix-community/fenix/df3c2e78ec13418f85c1f26e77a50f865ec57d38?narHash=sha256-%2Boo9W5rz03TjfpNqDSLEQwgKiuBbjrHdORyTHli2RuM%3D' (2025-12-01)
  → 'github:nix-community/fenix/f1cf6dcfc51a08e154ec753f11146dc1d95be1e5?narHash=sha256-EIP2/UXzbkb1ZWoa0pTwNv2ZivlfbRT%2B7j0fj36IhWg%3D' (2026-01-25)
• Updated input 'fenix/rust-analyzer-src':
    'github:rust-lang/rust-analyzer/d646b23f000d099d845f999c2c1e05b15d9cdc78?narHash=sha256-vR3vU9AwzMsBvjNeeG2inA5W/2MwseFk5NIIrLFEMHk%3D' (2025-11-30)
  → 'github:rust-lang/rust-analyzer/cc76a8a0c6039abb17e005aa5f96c9d13d4d9665?narHash=sha256-LoyIkk68hFEwE49o8rzYK50bqX8jWhjcxpYLz2lBCbI%3D' (2026-01-24)
• Updated input 'nixpkgs':
    'github:NixOS/nixpkgs/23258e03aaa49b3a68597e3e50eb0cbce7e42e9d?narHash=sha256-nA5ywiGKl76atrbdZ5Aucd8SjF/v8ew9b9QsC%2BMKL14%3D' (2025-11-30)
  → 'github:NixOS/nixpkgs/48698d12cc10555a4f3e3222d9c669b884a49dfe?narHash=sha256-yxgb4AmkVHY5OOBrC79Vv6EVd4QZEotqv%2B6jcvA212M%3D' (2026-01-25)

Author: sunng87