fix: CI: concourse: Use GHCR github-status image

[mook-as]

Description

Docker Hub has put in quotas for image pulling; this is causing an issue for our CI pipelines. Copy the image to the GitHub container registry (which currently has no limits). There is currently no pipeline to push to the GitHub container registry; it's just the latest image on Docker Hub for now.

Motivation and Context

See #1557 — this doesn't fix the whole issue yet, just one of the images.

How Has This Been Tested?

Hasn't been tested yet; I have confirmed that I can pull the image without logging in. (It appears that the docker client in OpenSUSE Leap 15.1 (19.03.11) cannot login to GHCR.)

Types of changes

• [x] Bug fix (non-breaking change which fixes an issue)
• [ ] New feature (non-breaking change which adds functionality)
• [ ] Breaking change (fix or feature that would cause existing functionality to change)

Checklist:

• [x] My code has security implications.
• [x] My code follows the code style of this project.
• [ ] My change requires a change to the documentation.
• [ ] I have updated the documentation accordingly.

[mook-as]

We may or may not use this org later, but for now we have #1573 already.