Update AutoShape.forward() model.classes example

[glenn-jocher]

🛠️ PR Summary

_{Made with ❤️ by Ultralytics Actions}

🌟 Summary

Improves documentation for class filtering in model wrapper.

📊 Key Changes

• Enhanced code comment for the classes variable in AutoShape class to clarify its purpose.

🎯 Purpose & Impact

• 📝 Provides clearer guidelines for developers and users on how to filter detections by specific categories (like persons, cats, and dogs in the COCO dataset).
• 🤖 Helps to avoid confusion when using the model for inference, leading to a better user experience.

[glenn-jocher]

/rebase