flake.lock: Update (#302)

Flake lock file updates:

• Updated input 'nixpkgs':
    'https://api.flakehub.com/f/pinned/NixOS/nixpkgs/0.1.628669%2Brev-6c0b7a92c30122196a761b440ac0d46d3d9954f1/018f953e-20fc-7f4d-a87a-92641cb7b27a/source.tar.gz?narHash=sha256-sowPU%2BtLQv8GlqtVtsXioTKeaQvlMz/pefcdwg8MvfM%3D' (2024-05-19)
  → 'https://api.flakehub.com/f/pinned/NixOS/nixpkgs/0.1.629267%2Brev-3eaeaeb6b1e08a016380c279f8846e0bd8808916/018f9d38-4f13-7e97-b2ab-5152b0dd73ec/source.tar.gz?narHash=sha256-pU9ViBVE3XYb70xZx%2BjK6SEVphvt7xMTbm6yDIF4xPs%3D' (2024-05-21)
• Updated input 'nixvim':
    'github:nix-community/nixvim/5b09c711e28e9b41ad0fe094e7d62232c1e7c3de?narHash=sha256-zZBIPlqtg/E8i820VwiV3pxiMs4xzM1bAnoZD6Nnpxg%3D' (2024-05-20)
  → 'github:nix-community/nixvim/5d2e01495944dcf7cf7ee53a7074c4010165d756?narHash=sha256-1LyTvpjb8Cmlg3TRnP56rvqK1WSNa518pD6F0tjgM%2BU%3D' (2024-05-21)

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