Bump torch>=1.8.0 and torchvision>=0.9.0

[glenn-jocher]

🤖 Generated by Copilot at 243e103

Summary

📝🔥🚀

This pull request updates the codebase and documentation to use PyTorch 1.8.0 as the minimum requirement for the yolov5 project. This ensures compatibility and performance with the latest PyTorch and torchvision packages.

Sing, O Muse, of the swift and skillful changes
That the wise and resourceful developers made
To the yolov5 project, the glorious offspring
Of the mighty and radiant PyTorch framework.

Walkthrough

• Update PyTorch dependency to 1.8.0 and Python environment to 3.8.0 for the yolov5 project (link, link, link, link, link, link)

• Change the CI testing matrix in .github/workflows/ci-testing.yml to use PyTorch 1.8.0 and Python 3.8.0 for the ubuntu-latest combination (link, link)
• Update the README files in README.md and README.zh-CN.md to inform the users of the minimum PyTorch requirement and the recommended Python environment (link, link, link)
• Remove the comment about torch 1.7.0 compatibility in models/experimental.py as it is no longer relevant (link)

🛠️ PR Summary

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🌟 Summary

Update minimum PyTorch version from 1.7.0 to 1.8.0 across the repository.

📊 Key Changes

• Updated Python CI testing to use PyTorch version 1.8.0 and torchvision 0.9.0.
• Adjusted the Python and PyTorch version requirements in the README files accordingly.
• Modified compatibility updates in models/experimental.py.

🎯 Purpose & Impact

• Ensures compatibility with PyTorch version 1.8.0, providing users with the benefits of newer PyTorch features and optimizations. 🆕
• Aligns the codebase with current best practices by using a more up-to-date version of PyTorch. ✔️
• Enhances maintainability and support for users who have upgraded to newer versions of PyTorch. 🛠️