flake.lock: Update

Flake lock file updates:

• Updated input 'fenix':
    'github:nix-community/fenix/aaeaf4574767a0f5ed1787e990139aefcf4db103?narHash=sha256-iGb6ptUaNBOCftKnNJiWT5z1ftngfNtwqJkD8Z9Vwfw%3D' (2024-03-30)
  → 'github:nix-community/fenix/6e4233dc54850e8aff6eff401400e9a9343881eb?narHash=sha256-7ehq0nfRHpU3oNAkRpklaDxQZUpuaUig2sR2LI%2BIL/U%3D' (2024-08-15)
• Updated input 'fenix/rust-analyzer-src':
    'github:rust-lang/rust-analyzer/f5a9250147f6569d8d89334dc9cca79c0322729f?narHash=sha256-dyezzeSbWMpflma%2BE9USmvSxuLgGcNGcGw3cOnX36ko%3D' (2024-03-29)
  → 'github:rust-lang/rust-analyzer/64a140527b383e3a2fe95908881624fc5374c60c?narHash=sha256-AT6K9JREduWC1zcIJIx8JTZa4sYZD6VvyB/xRnjphqY%3D' (2024-08-14)
• Updated input 'nixpkgs':
    'github:nixos/nixpkgs/d8fe5e6c92d0d190646fb9f1056741a229980089?narHash=sha256-iMUFArF0WCatKK6RzfUJknjem0H9m4KgorO/p3Dopkk%3D' (2024-03-29)
  → 'github:nixos/nixpkgs/c3aa7b8938b17aebd2deecf7be0636000d62a2b9?narHash=sha256-med8%2B5DSWa2UnOqtdICndjDAEjxr5D7zaIiK4pn0Q7c%3D' (2024-08-14)
• Updated input 'rust-overlay':
    'github:oxalica/rust-overlay/db12d0c6ef002f16998723b5dd619fa7b8997086?narHash=sha256-6eaaoJUkr4g9J/rMC4jhj3Gv8Sa62rvlpjFe3xZaSjM%3D' (2024-07-02)
  → 'github:oxalica/rust-overlay/07105b5f550665ff417487febcd6bf5dd071b931?narHash=sha256-tfPBU%2BfK6YYMZvNsOYHv6JzBa8XKuhtfu8Cb9lnri1w%3D' (2024-08-17)