flake.lock: Update

Flake lock file updates:

• Updated input 'fenix':
    'github:nix-community/fenix/73d13a8c584a2f8b35677a38e86ba148dc99d2f3' (2023-05-20)
  → 'github:nix-community/fenix/207c664b137bf699b276481614d176b9bbe9f537' (2023-07-08)
• Updated input 'fenix/rust-analyzer-src':
    'github:rust-lang/rust-analyzer/bb78059be4d090571bd70de57831f84eee5be678' (2023-05-19)
  → 'github:rust-lang/rust-analyzer/db0add1ce92af58a92b2a80990044ae21713ae29' (2023-07-07)
• Updated input 'nixpkgs':
    'github:NixOS/nixpkgs/eea79d584eff53bf7a76aeb63f8845da6d386129' (2023-05-20)
  → 'github:NixOS/nixpkgs/ed6afb10dfdfc97b6bcf0703f1bad8118e9e961b' (2023-07-08)
• Updated input 'utils':
    'github:numtide/flake-utils/cfacdce06f30d2b68473a46042957675eebb3401' (2023-04-11)
  → 'github:numtide/flake-utils/dbabf0ca0c0c4bce6ea5eaf65af5cb694d2082c7' (2023-06-25)