fix: Change build args to list of strings

[NavarrePratt]

The build-args should be passed in as a new-line delimted list of strings, like in the slurm.yml workload. Without these changes, the action wasn't properly passing in the commit and would use the cached layer when building the docker image instead of pulling down the new changes from kuberenetes-cloud.

Build using cached layers instead of pulling kubernetes-cloud Build with this fix properly pulling down kubernetes-cloud

[github-actions[bot]]

@NavarrePratt Build complete, success: https://github.com/coreweave/ml-containers/actions/runs/4185818831 Image: ghcr.io/coreweave/ml-containers/gpt-neox-mpi:npratt-fix-sd-inference-2cfbff3

[github-actions[bot]]

@NavarrePratt Build complete, success: https://github.com/coreweave/ml-containers/actions/runs/4185818825 Image: ghcr.io/coreweave/ml-containers/sd-finetuner:npratt-fix-sd-inference-2cfbff3

[github-actions[bot]]

@NavarrePratt Build complete, success: https://github.com/coreweave/ml-containers/actions/runs/4185818824 Image: ghcr.io/coreweave/ml-containers/sd-serializer:npratt-fix-sd-inference-2cfbff3

[github-actions[bot]]

@NavarrePratt Build complete, success: https://github.com/coreweave/ml-containers/actions/runs/4185818827 Image: ghcr.io/coreweave/ml-containers/sd-inference:npratt-fix-sd-inference-2cfbff3

[NavarrePratt]

Upon further testing this doesn't fix the issue.