flake.lock: Update

Flake lock file updates:

• Updated input 'fenix':
    'github:nix-community/fenix/c7e184561fe843abb861cd7d22c23066987078e2' (2022-04-06)
  → 'github:nix-community/fenix/5cbb7720dcbb684fd8375fdd915fb725a6c2178b' (2022-04-16)
• Updated input 'fenix/nixpkgs':
    'github:nixos/nixpkgs/bc4b9eef3ce3d5a90d8693e8367c9cbfc9fc1e13' (2022-04-03)
  → 'github:nixos/nixpkgs/5181d5945eda382ff6a9ca3e072ed6ea9b547fee' (2022-04-15)
• Updated input 'fenix/rust-analyzer-src':
    'github:rust-analyzer/rust-analyzer/2366d8e05f5f3585f95058fa7427cbde079914ed' (2022-04-05)
  → 'github:rust-analyzer/rust-analyzer/1c22537b3b7012f76952546ef90b18509a056690' (2022-04-15)
• Updated input 'naersk':
    'github:nix-community/naersk/d626f73332a8f587b613b0afe7293dd0777be07d' (2022-04-04)
  → 'github:nix-community/naersk/8cc379478819e6a22ce7595a761fe1e17c8d7458' (2022-04-16)
• Updated input 'naersk/nixpkgs':
    'github:NixOS/nixpkgs/30d3d79b7d3607d56546dd2a6b49e156ba0ec634' (2022-03-25)
  → 'github:NixOS/nixpkgs/faad370edcb37162401be50d45526f52bb16a713' (2022-04-16)
• Updated input 'nixpkgs':
    'github:NixOS/nixpkgs/30d3d79b7d3607d56546dd2a6b49e156ba0ec634' (2022-03-25)
  → 'github:NixOS/nixpkgs/faad370edcb37162401be50d45526f52bb16a713' (2022-04-16)
• Updated input 'utils':
    'github:numtide/flake-utils/0f8662f1319ad6abf89b3380dd2722369fc51ade' (2022-03-26)
  → 'github:numtide/flake-utils/a4b154ebbdc88c8498a5c7b01589addc9e9cb678' (2022-04-11)