remove GPU toolkit from CPU images

[casperdcl]

e.g. tested with ghcr.io/premai-io/audio-to-text-whisper-tiny-cpu:1.0.1 (source):

• docker run: takes ~60 sec and uses 25% of my CPU to process https://github.com/htrivedi99/prem-blogs/blob/main/quarterly-earnings-chatbot/nvidia_earnings_call.mp3
• docker run --gpus all: takes ~5sec and uses 100% of my GPU + 25% of my CPU... even though the image is labelled as -cpu (non-GPU)

Clearly some python dependency is pulling in CUDA libs.

$ docker run --rm -t ghcr.io/premai-io/audio-to-text-whisper-tiny-cpu pip list | grep nvidia
nvidia-cublas-cu11       11.10.3.66
nvidia-cuda-cupti-cu11   11.7.101
nvidia-cuda-nvrtc-cu11   11.7.99
nvidia-cuda-runtime-cu11 11.7.99
nvidia-cudnn-cu11        8.5.0.96
nvidia-cufft-cu11        10.9.0.58
nvidia-curand-cu11       10.2.10.91
nvidia-cusolver-cu11     11.4.0.1
nvidia-cusparse-cu11     11.7.4.91
nvidia-nccl-cu11         2.14.3
nvidia-nvtx-cu11         11.7.91

Need to remove this unnecessary bloat from CPU images.