Update requirements.txt comment spacing

[glenn-jocher]

🛠️ PR Summary

_{Made with ❤️ by Ultralytics Actions}

🌟 Summary

Update requirements.txt dependencies and comments

📊 Key Changes

• Fixed comment spacing for torchvision entry to maintain consistency.
• Added comment spacing for TensorRT export-related entries (nvidia-pyindex and nvidia-tensorrt).

🎯 Purpose & Impact

• 👓 Enhances readability and consistency in the requirements.txt, which benefits developers looking through dependencies.
• 📝 No direct impact on the functionality as the changes are purely cosmetic, but it contributes to a cleaner and more maintainable codebase.