check_requirements() Windows fix

[glenn-jocher]

🛠️ PR Summary

_{Made with ❤️ by Ultralytics Actions}

🌟 Summary

Enhanced package installation reliability in the YOLOv5 codebase.

📊 Key Changes

• Modified the command used to install missing packages within the check_requirements function.

🎯 Purpose & Impact

• This change aims to improve the consistency of package installations by removing the single quotes from around the package name in the installation command.
• Users may experience smoother installation of dependencies, especially in environments where the previous syntax could have caused issues.
• The update could help avoid errors related to package installation during setup or use of YOLOv5, thereby enhancing user experience. 🛠️💡