Update check_requirements() multiple string

[glenn-jocher]

Signed-off-by: Glenn Jocher [email protected]

🛠️ PR Summary

_{Made with ❤️ by Ultralytics Actions}

🌟 Summary

Improved grammar in requirement update logging.

📊 Key Changes

• Modified how missing requirements are logged by adding a conditional 's' to 'requirement' based on the number of missing packages.

🎯 Purpose & Impact

• This change improves the readability of logs by ensuring that the singular or plural form of 'requirement' is used correctly.
• Users will experience clearer communication when the system auto-updates dependencies, enhancing user experience.