Configure GitHub Actions to push container image to GitHub Container Registry (in addition to Docker Hub)

[eecavanna]

Description

In this branch, I updated a GitHub Actions workflow so that, when it builds a container image and pushes it to Docker Hub, it also pushes a copy to GitHub Container Registry. That will make nmdc-runtime work more similarly to other NMDC products/applications (i.e. nmdc-server, nmdc-edge, and nmdc-aggregator).

Fixes #564

Type of change

Please delete options that are not relevant.

• [ ] Bug fix (non-breaking change which fixes an issue)
• [x] New feature (non-breaking change which adds functionality)
• [ ] Breaking change (fix or feature that would cause existing functionality to not work as expected)
• [ ] This change requires a documentation update

How Has This Been Tested?

It has not been tested yet. The final test will be whether Runtime package(s) appear at https://github.com/orgs/microbiomedata/packages once this new GHA workflow runs.

Configuration Details: none

Checklist:

• [ ] My code follows the style guidelines of this project (have you run black nmdc_runtime/?)
• [x] I have performed a self-review of my code
• [x] I have commented my code, particularly in hard-to-understand areas
• [ ] I have made corresponding changes to the documentation (in docs/ and in https://github.com/microbiomedata/NMDC_documentation/?)
• [ ] I have added tests that prove my fix is effective or that my feature works, incl. considering downstream usage (e.g. https://github.com/microbiomedata/notebook_hackathons) if applicable.
• [ ] New and existing unit and functional tests pass locally with my changes (make up-test && make test-run)

[eecavanna]

Thanks, @dwinston. Here goes, fingers crossed! 🤞 😄