coremltools>=5.2 for CoreML export

[glenn-jocher]

🛠️ PR Summary

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🌟 Summary

Update to CoreML tools dependency in YOLOv5.

📊 Key Changes

• The version requirement for coremltools has been updated from >=4.1 to >=5.2.

🎯 Purpose & Impact

• Purpose: To ensure compatibility with the latest features and improvements in coremltools.
• Impact: Users exporting YOLOv5 models to CoreML format will benefit from enhancements and possibly better performance or support that comes with the newer version of coremltools. Developers need to update their environments accordingly. 🚀