chore(example/share-services/northwind): Update flake.lock

Flake lock file updates:

• Updated input 'flake-parts':
    'github:hercules-ci/flake-parts/2cccadc' (2025-11-21)
  → 'github:hercules-ci/flake-parts/a34fae9' (2025-12-15)
• Updated input 'flake-parts/nixpkgs-lib':
    'github:nix-community/nixpkgs.lib/719359f' (2025-10-29)
  → 'github:nix-community/nixpkgs.lib/2075416' (2025-12-14)
• Updated input 'nixpkgs':
    'github:nixos/nixpkgs/a672be6' (2025-12-05)
  → 'github:nixos/nixpkgs/3edc4a3' (2025-12-27)
• Updated input 'services-flake':
    'github:juspay/services-flake/648cf66' (2025-12-05)
  → 'github:juspay/services-flake/8b6244f' (2025-12-08)

Author: github-actions[bot]