✨ feat(chat.py): use LRUCache from cachetools to limit the size of flow_data_store

The cachetools package is added as a dependency to improve caching. In chat.py, a ValueError is raised if no ID is provided in init_build to prevent errors. The flow_data_store dictionary is replaced with an LRUCache from cachetools to limit the size of the cache to 10 items. This improves performance by reducing the memory usage of the application.
📦 chore(pyproject.toml): add cachetools dependency to improve caching
🐛 fix(chat.py): raise ValueError if no ID is provided in init_build