flake.lock: Update (ggml-org#9162)

Flake lock file updates:

• Updated input 'nixpkgs':
    'github:NixOS/nixpkgs/c3aa7b8938b17aebd2deecf7be0636000d62a2b9?narHash=sha256-med8%2B5DSWa2UnOqtdICndjDAEjxr5D7zaIiK4pn0Q7c%3D' (2024-08-14)
  → 'github:NixOS/nixpkgs/c374d94f1536013ca8e92341b540eba4c22f9c62?narHash=sha256-Z/ELQhrSd7bMzTO8r7NZgi9g5emh%2BaRKoCdaAv5fiO0%3D' (2024-08-21)

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

common : Update stb_image.h to latest version (ggml-org#9161)

* Update stb_image.h to latest version

Fixes ggml-org#7431

* Update .ecrc