flake.lock: Update (#551)

Flake lock file updates:

• Updated input 'home-manager':
    'github:nix-community/home-manager/10e99c43cdf4a0713b4e81d90691d22c6a58bdf2?narHash=sha256-CyCZFhMUkuYbSD6bxB/r43EdmDE7hYeZZPTCv0GudO4%3D' (2024-12-28)
  → 'github:nix-community/home-manager/5f6aa268e419d053c3d5025da740e390b12ac936?narHash=sha256-C73gLFnEh8ZI0uDijUgCDWCd21T6I6tsaWgIBHcfAXg%3D' (2025-01-01)
• Updated input 'nixvim':
    'github:nix-community/nixvim/bc87d91273928c97a47eab0df9b303bb45adc6f4?narHash=sha256-AnTW4OA8vW6CGqNJQZ/jV%2Bi9ei7h7g%2BhtGGdshWmQSo%3D' (2024-12-31)
  → 'github:nix-community/nixvim/87ee660991fa0e1b7b4e3f43a6dd1d126e64f3fa?narHash=sha256-g2kXpnAHXpwDfz/4Q2Kwzmee%2BQQKIhmo4DC6JXA8d18%3D' (2025-01-01)

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