Correct the output dir in dataloaders.py

[ya0guang]

🛠️ PR Summary

_{Made with ❤️ by Ultralytics Actions}

🌟 Summary

Improved directory naming for file exports in data preprocessing.

📊 Key Changes

• Changed the output directory for certain image exports from "classifier" to "classification".

🎯 Purpose & Impact

• 🎨 Enhances clarity and consistency in directory naming conventions.
• 🗂 May affect scripts or users expecting the old "classifier" directory, requiring updates to accommodate the new "classification" path.
• 🔄 Users should find it more intuitive to locate and manage exported image data tied to classification tasks.

[github-actions]

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[glenn-jocher]

@ya0guang thank you for the PR!