requirements.txt: add missing onnx and bump onnxruntime to 1.14.1

[tiborvass]

Thanks for figuring out how to statically compile onnxruntime! :)

When I tried your project, I had to add onnx as a requirement or else I had an error. I also figured I'd bump the onnxruntime requirement to the latest. Hope you or someone will find it useful, cheers!

[olilarkin]

thanks!