flake.lock: Update

Flake lock file updates:

• Updated input 'fenix':
    'github:nix-community/fenix/d6f9bdfb4a25395b15f6c6feba3d0bba5e62b3ce' (2022-12-31)
  → 'github:nix-community/fenix/2fa6ef94550e2e8b5e47fa3b0655edcacbb65cb6' (2023-01-07)
• Updated input 'fenix/rust-analyzer-src':
    'github:rust-lang/rust-analyzer/0d76b94c90a20c20d3e57ea1ab03d9afa00dee72' (2022-12-30)
  → 'github:rust-lang/rust-analyzer/f1a99014b356c6aa41a69ceecf1f8cc68d901006' (2023-01-06)
• Updated input 'sops-nix':
    'github:Mic92/sops-nix/855b8d51fc3991bd817978f0f093aa6ae0fae738' (2022-12-25)
  → 'github:Mic92/sops-nix/b35586cc5abacd4eba9ead138b53e2a60920f781' (2023-01-01)
• Updated input 'sops-nix/nixpkgs-stable':
    'github:NixOS/nixpkgs/939c05a176b8485971463c18c44f48e56a7801c9' (2022-12-24)
  → 'github:NixOS/nixpkgs/feda52be1d59f13b9aa02f064b4f14784b9a06c8' (2022-12-31)