ci: fix docker image smoke test to use python --version

[nacholiya]

Summary

Fixes CI failure in Docker image workflow caused by an invalid container smoke test.

Root Cause

The workflow attempted to run the image with --help, but the container does not expose a CLI entrypoint.

Fix

Replaced the smoke test with python --version to verify the container starts correctly.

Fixes #133

[endomorphosis]

@nacholiya i am doing a significant amount of refactoring an integration of this package, and the ipfs_datasets_py, ipfs_accelerate_py, and swissknife to all work together.

i will let you know when the integrations have gotten working well.

[nacholiya]

Thanks for the update, appreciate the context 👍
No rush from my side — happy to wait until the refactor settles.

Let me know if you want me to rebase or adjust the PR later.