chore(nix): update `flake.lock`
Flake lock file updates:
• Updated input 'advisory-db':
'github:rustsec/advisory-db/f2ae5fc' (2026-05-16)
→ 'github:rustsec/advisory-db/831c50f' (2026-05-23)
• Updated input 'blockfrost-tests':
'github:blockfrost/blockfrost-tests/7c8dfa8' (2026-05-15)
→ 'github:blockfrost/blockfrost-tests/72316a2' (2026-05-20)
• Updated input 'crane':
'github:ipetkov/crane/6d015ea' (2026-05-06)
→ 'github:ipetkov/crane/edb3889' (2026-05-18)
• Updated input 'fenix':
'github:nix-community/fenix/ecd6d4f' (2026-05-16)
→ 'github:nix-community/fenix/4f37db7' (2026-05-23)
• Updated input 'fenix/rust-analyzer-src':
'github:rust-lang/rust-analyzer/1a68212' (2026-05-15)
→ 'github:rust-lang/rust-analyzer/56dc60d' (2026-05-22)
• Updated input 'nixpkgs':
'github:nixos/nixpkgs/d7a713c' (2026-05-14)
→ 'github:nixos/nixpkgs/687f05a' (2026-05-18)