check_git_status() improvements

[glenn-jocher]

Enhanced git status checks and messages.

🛠️ PR Summary

_{Made with ❤️ by Ultralytics Actions}

🌟 Summary

Clean-up in training script and improved check for repository updates.

📊 Key Changes

• Removed unnecessary warning message related to hyperparameter renaming.
• Simplified logging of hyperparameters in the training script.
• Introduced a new function check_online to verify internet connectivity.
• Refined the git status check to suggest updates for YOLOv5 repository.

🎯 Purpose & Impact

• Enhances the usability of training scripts by omitting outdated compatibility warnings. 👍
• Streamlines user interface by normalizing the logging capitalization. 🔤
• The check_online function allows for more robust detection of internet access, improving the functionality of remote operations. 🌐
• Improved git status checking keeps users better informed about the need to pull updates, ensuring they have the latest features and bug fixes. 🔄