Update default COCO path

[glenn-jocher]

🛠️ PR Summary

_{Made with ❤️ by Ultralytics Actions}

🌟 Summary

Updated the directory path for COCO source data in the JSON to YOLO conversion script.

📊 Key Changes

• Changed the default directory path for COCO JSON format annotations.

🎯 Purpose & Impact

• 🎯 The update ensures the script points to the correct directory for users working with Objects365 dataset—a potentially different dataset than COCO, but using the same format.
• 🚀 This change streamlines the workflow for users working with Objects365, reducing the need for manual path adjustments and potential errors.
• 📈 Impact: Users working with datasets using the COCO JSON format may find this change particularly useful, improving usability and accessibility of the conversion script.