the value should be a list to unpack

[tkianai]

🛠️ PR Summary

_{Made with ❤️ by Ultralytics Actions}

🌟 Summary

Improved label caching by specifying default cache structure for exceptions in YOLOv5 datasets.

📊 Key Changes

• Changed how label caching handles exceptions: instead of assigning None to a cache entry, it now assigns [None, None] to maintain data structure continuity.

🎯 Purpose & Impact

• Consistency: Helps maintain a constant data structure even when an error occurs, improving data handling robustness.
• Error Handling: Enhances the clarity of error outputs, making it easier to debug issues with label loading.
• User Experience: Indirectly benefits users by possibly reducing label-related errors during model training, leading to a smoother experience.