flake: update inputs (#283)

Flake lock file updates:

• Updated input 'nixpkgs':
    'github:NixOS/nixpkgs/c374d94f1536013ca8e92341b540eba4c22f9c62?narHash=sha256-Z/ELQhrSd7bMzTO8r7NZgi9g5emh%2BaRKoCdaAv5fiO0%3D' (2024-08-21)
  → 'github:NixOS/nixpkgs/d0e1602ddde669d5beb01aec49d71a51937ed7be?narHash=sha256-pP3Azj5d6M5nmG68Fu4JqZmdGt4S4vqI5f8te%2BE/FTw%3D' (2024-08-24)
• Updated input 'rust-overlay':
    'github:oxalica/rust-overlay/19fda552b69513df7b6aa5fcfd1412c0221467b1?narHash=sha256-u1xzgrdRTL0DQhjXMgmEvl75IrL8zGf0RS34IQJXxeU%3D' (2024-08-25)
  → 'github:oxalica/rust-overlay/19b70f147b9c67a759e35824b241f1ed92e46694?narHash=sha256-ap2jIQi/FuUHR6HCht6ASWhoz8EiB99XmI8Esot38VE%3D' (2024-08-26)

Co-authored-by: github-actions[bot] <github-actions[bot]@users.noreply.github.com>