v4.0.1 : multi-platform image building

The reason this is simply a patch release is because very little of the container-internal software has changed. ONNX had to be bumped to 1.15 but besides that, only the removal of an old, now meaningless, compile flag was implemented in the Dockerfile. The rest of the changes and work was done in the CI, making sure that the builder workflow could be done across many architectures at once and setting up a self-hosted runner at UMN for our very-long builds.

What's Changed

• refactor builder workflow by @tomeichlersmith in #62
• multi platform image building by @tomeichlersmith in #63

Other Contributions

• @therwig did some manual testing of different images on his Apple M1 computer to double check that the arm builds were functional.

Full Changelog: v4.0.0...v4.0.1