The gpt-2 excutable is here
https://drive.google.com/file/d/1xeT75QmP8yKXo20mOyiUi5nP3dHcYY0U/view?usp=sharing
The model binary is here.
https://huggingface.co/ggerganov/ggml/resolve/main/ggml-model-gpt-2-117M.bin
You need to upload both to Code Interpreter.