Failed to build onnx ERROR: Could not build wheels for onnx, which is required to install pyproject.toml-based projects

As an AI language model, I can suggest you the following solutions to troubleshoot the error:

1. Check the system requirements: Ensure that your system meets all the requirements for building and installing the ONNX package. Some of the requirements include CMake, Python, and NumPy.

2. Update the dependencies: Make sure that all the dependencies required by the ONNX package are up to date. You can use pip to update the dependencies.

3. Clean the build directory: Try cleaning the build directory and rebuilding the package. You can use the following command to clean the build directory:

   python setup.py clean

4. Use a virtual environment: Create a virtual environment and install the ONNX package within the environment. This will help isolate the package from the rest of the system and prevent conflicts with other packages.

5. Try a different installation method: If none of the above solutions work, try installing the ONNX package using a different installation method, such as conda or Docker.

Hopefully, one of these solutions will help you resolve the error and successfully install the ONNX package.