chore(nix): update `flake.lock`
Flake lock file updates:
• Updated input 'advisory-db':
'github:rustsec/advisory-db/881a159' (2026-05-07)
→ 'github:rustsec/advisory-db/f2ae5fc' (2026-05-16)
• Updated input 'blockfrost-tests':
'github:blockfrost/blockfrost-tests/dac734c' (2026-05-15)
→ 'github:blockfrost/blockfrost-tests/7c8dfa8' (2026-05-15)
• Updated input 'fenix':
'github:nix-community/fenix/f54d645' (2026-05-09)
→ 'github:nix-community/fenix/ecd6d4f' (2026-05-16)
• Updated input 'fenix/rust-analyzer-src':
'github:rust-lang/rust-analyzer/73ca1d4' (2026-05-08)
→ 'github:rust-lang/rust-analyzer/1a68212' (2026-05-15)
• Updated input 'flake-parts':
'github:hercules-ci/flake-parts/0678d89' (2026-05-05)
→ 'github:hercules-ci/flake-parts/f7c1a2d' (2026-05-13)
• Updated input 'nixpkgs':
'github:nixos/nixpkgs/0c88e1f' (2026-05-05)
→ 'github:nixos/nixpkgs/d7a713c' (2026-05-14)