Update train.py

[ShubhamPhapale]

updated deprecated call

🛠️ PR Summary

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🌟 Summary

Updated AMP (Automatic Mixed Precision) autocast usage for compatibility with PyTorch 2.0+.

📊 Key Changes

• Replaced torch.cuda.amp.autocast(amp) with torch.amp.autocast('cuda', amp) in the training script.

🎯 Purpose & Impact

• Purpose: Aligns the code with PyTorch 2.0+ updates, making YOLOv5 compatible with newer PyTorch versions.
• Impact: Prevents potential errors or deprecation warnings, ensuring smoother training experiences for users upgrading to the latest PyTorch versions. 🚀

[github-actions]

All Contributors have signed the CLA. ✅
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[UltralyticsAssistant]

👋 Hello @ShubhamPhapale, thank you for submitting a ultralytics/yolov5 🚀 PR! To ensure a seamless integration of your work, please review the following checklist:

• ✅ Define a Purpose: Clearly explain the purpose of your fix or feature in your PR description, and link to any relevant issues. Ensure your commit messages are clear, concise, and adhere to the project's conventions.
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• ✅ Update Documentation: Update the relevant documentation for any new or modified features.
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For more guidance, please refer to our Contributing Guide. Don’t hesitate to leave a comment if you have any questions. Thank you for contributing to Ultralytics! 🚀

🛠️ Notes

It looks like your PR updates AMP autocast usage for compatibility with PyTorch 2.0+, which is an important improvement.

If applicable, please include a minimum reproducible example (MRE) so we can fully understand and test the impact of this change. For example, providing specific training scenarios where the prior implementation failed due to autograd issues with PyTorch 2.0+ would help validate this fix.

An Ultralytics engineer will also review this PR shortly. Stay tuned for additional feedback! 🚀

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[ShubhamPhapale]

I have read the CLA Document and I sign the CLA