Update CI benchmarks to ONNX autoinstall

[glenn-jocher]

Avoids openvino-dev conflicts.

🛠️ PR Summary

_{Made with ❤️ by Ultralytics Actions}

🌟 Summary

Improvement of CI testing dependencies for the Ultralytics YOLOv5 project.

📊 Key Changes

• Removed onnx and onnxruntime from the CI testing requirements.

🎯 Purpose & Impact

• 🔍 The purpose of this change is to streamline CI dependencies, potentially reducing installation time and limiting the scope of testing to more directly related components.
• 💻 For users, this might mean slightly faster CI builds and fewer dependency-related issues during continuous integration testing.
• 🚀 This could lead to more efficient development cycles and more stable software releases in the future.