Remove tensorrt pip install check

[glenn-jocher]

Resolves #7431

🛠️ PR Summary

_{Made with ❤️ by Ultralytics Actions}

🌟 Summary

Streamlined import process for NVIDIA TensorRT in export script.

📊 Key Changes

• Removed check_requirements function for TensorRT import in export.py.
• Direct import of TensorRT library now without the prior version check.

🎯 Purpose & Impact

• Simplification: The change makes the codebase cleaner by eliminating the version check before importing TensorRT.
• Ease of use: Users can now expect a more straightforward import process for TensorRT, which is used for optimizing deep learning models.
• Potential Performance Improvement: As the development moves forward, the YOLOv5 model can leverage the latest TensorRT optimizations without version restrictions, potentially improving performance for end-users. 🚀
• Update Readiness: Encourages users to maintain the latest version of TensorRT, ensuring compatibility with new features and optimizations provided by Ultralytics.