chore(flake): update inputs

Flake lock file updates:

• Updated input 'nixpkgs':
    'github:NixOS/nixpkgs/cb9a96f23c491c081b38eab96d22fa958043c9fa?narHash=sha256-IAoYyYnED7P8zrBFMnmp7ydaJfwTnwcnqxUElC1I26Y%3D' (2024-08-04)
  → 'github:NixOS/nixpkgs/5e0ca22929f3342b19569b21b2f3462f053e497b?narHash=sha256-M0xJ3FbDUc4fRZ84dPGx5VvgFsOzds77KiBMW/mMTnI%3D' (2024-08-09)
• Updated input 'rust-overlay':
    'github:oxalica/rust-overlay/d720bf3cebac38c2426d77ee2e59943012854cb8?narHash=sha256-8Pncp8IKd0f0N711CRrCGTC4iLfBE%2B/5kaMqyWxnYic%3D' (2024-08-07)
  → 'github:oxalica/rust-overlay/615cfd85b4d9c51811a8d875374268fab5bd4089?narHash=sha256-9iDTrfVM%2Bmbcad31a47oqW8t8tfSA4C/si6F8F2DO/w%3D' (2024-08-10)

Author: github-actions[bot]