flake.lock: Update

Flake lock file updates:

• Updated input 'flake-compat':
    'github:edolstra/flake-compat/64a525ee38886ab9028e6f61790de0832aa3ef03' (2022-03-25)
  → 'github:edolstra/flake-compat/b4a34015c698c7793d592d66adbab377907a2be8' (2022-04-19)
• Updated input 'nixpkgs':
    'github:NixOS/nixpkgs/710fed5a2483f945b14f4a58af2cd3676b42d8c8' (2022-03-30)
  → 'github:NixOS/nixpkgs/87d34a6b8982e901b8e50096b8e79ebc0e66cda0' (2022-04-24)
• Updated input 'stable':
    'github:NixOS/nixpkgs/0aac710801aec4ba545527cf41a5706028fe6271' (2022-04-03)
  → 'github:NixOS/nixpkgs/c254b8c915ac912ae9ee9dc74eac555ccbf33795' (2022-04-24)
• Updated input 'utils':
    'github:numtide/flake-utils/0f8662f1319ad6abf89b3380dd2722369fc51ade' (2022-03-26)
  → 'github:numtide/flake-utils/a4b154ebbdc88c8498a5c7b01589addc9e9cb678' (2022-04-11)