flake.lock: Update

Flake lock file updates:

• Updated input 'crane':
    'github:ipetkov/crane/220387ac8e99cbee0ca4c95b621c4bc782b6a235' (2024-04-09)
  → 'github:ipetkov/crane/cc1c68d5a39661951c0ad8567156452a5eda15e4' (2024-05-01)
• Updated input 'nixpkgs':
    'github:nixos/nixpkgs/2b80ce7707aedcb79be09e412b6dd6c15c578ab2' (2024-04-15)
  → 'github:nixos/nixpkgs/cf8cc1201be8bc71b7cbbbdaf349b22f4f99c7ae' (2024-04-28)
• Updated input 'rust-overlay':
    'github:oxalica/rust-overlay/847bc25ebab8dc72a86d2b1f0c088740eebbb1b8' (2024-04-16)
  → 'github:oxalica/rust-overlay/ce35c36f58f82cee6ec959e0d44c587d64281b6f' (2024-04-30)