Update Objects365.yaml val count

[glenn-jocher]

Follows improved validation set autodownlod in #5194

🛠️ PR Summary

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🌟 Summary

Update to the validation set size in Objects365 dataset configuration.

📊 Key Changes

• 🖼 Updated the number of validation images from 5,570 to 80,000 in the Objects365 dataset configuration file.

🎯 Purpose & Impact

• 🎯 Ensures more comprehensive validation by increasing the dataset size, leading to potentially better model performance and generalization.
• 💪 Provides a larger dataset for evaluating model accuracy, which could lead to more robust AI models.
• 👩‍💻 Helps developers and researchers to train models with a more extensive set of validation data, improving the reliability of performance metrics.