reduce build size by mounting cache

[technillogue]

when #17 switched to uninstalling torch then reinstalling prerelease torch, it added cached wheels to the final image. by mounting the pip cache, we speed up builds and reduce final image size

[yorickvP]

How about just:

  python_packages:
    - "numpy<2"
    - "einops==0.8.0"
    - "fire >= 0.6.0"
    - "huggingface-hub==0.24.3"
    - "safetensors==0.4.3"
    - "sentencepiece==0.2.0"
    - "transformers==4.43.3"
    - "tokenizers==0.19.1"
    - "protobuf==5.27.2"
    - "diffusers==0.29.2"
    - "loguru==0.7.2"
    - "pybase64==1.4.0"
    - "pydash==8.0.3"
    - https://download.pytorch.org/whl/nightly/cu124/torch-2.6.0.dev20240918%2Bcu124-cp311-cp311-linux_x86_64.whl
    - https://download.pytorch.org/whl/nightly/cu124/torchaudio-2.5.0.dev20240918%2Bcu124-cp311-cp311-linux_x86_64.whl
    - https://download.pytorch.org/whl/nightly/cu124/torchvision-0.20.0.dev20240918%2Bcu124-cp311-cp311-linux_x86_64.whl
    - https://download.pytorch.org/whl/nightly/pytorch_triton-3.1.0%2B5fe38ffd73-cp311-cp311-linux_x86_64.whl

[daanelson]

good stuff, I was hastily installing nightlies here and made some incorrect assumptions about how we deal with base images. @yorickvP think that's a lot cleaner; let's test that and merge if all looks good.