Fix 'PyTorch starting from' for URL weights

[glenn-jocher]

Follows #4823

🛠️ PR Summary

_{Made with ❤️ by Ultralytics Actions}

🌟 Summary

Refinement to logging output in the export script of the YOLOv5 repository.

📊 Key Changes

• The export script now references file instead of weights when printing the starting file size.

🎯 Purpose & Impact

• Clarifies the log message by printing the correct file name that is being processed.
• The update has a minor impact but improves the accuracy of the information provided to the user during the export process. 🧐
• Users will benefit from more accurate feedback when exporting their models, enhancing usability. 👍