Standardize Docker CI to use ghcr

[benkoppe]

Summary

The current CI uses ghcr for pull requests, and some DockerHub account for the tip of master. Should this PR be merged, the DockerHub account is ditched in favor of ghcr everywhere.

It also renames the workflow tracking master to "Continuous Deployment of Master" for clarity, as there is no longer a concept of "Staging". It adds github.repository_owner to the tags for both cd-workflow.yml and ci-container.yml, as this is our last chance to ensure the highest level of clarity possible in our Docker image names.

Finally, the PR cleans up usage of the docker-build-push.yml workflow to ensure our Actions work again, as secrets: inherit sadly cannot be mixed with declared secrets. The mixing of secrets is fixed with the standardization of ghcr as a Docker repository.

• standardize ghcr usage in favor of DockerHub
• clean up docker-build-push.yml to remove now-unnecessary registry/login inputs
• add github.repository_owner to Docker image tags

[dti-github-bot]

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