migrate official docker container to GHCR

[slingamn]

Docker Hub changed their TOS; you have to apply for participation now and agree to these terms:

While the Publisher retains the Open Source project status, the Publisher agrees to -
Become a Docker public reference for press releases, blogs, webinars, etc
Create joint blogs, webinars and other marketing content
Create explicit links to their Docker Hub repos, with no ‘wrapping’ or hiding sources of their images
Include information about Docker on the website and in documentation

This seems a little weird. Let's just switch to GHCR: https://docs.github.com/en/packages/working-with-a-github-packages-registry/working-with-the-container-registry

[slingamn]

This is kind of painful, you have to issue a PAT (it's recommended to specify an expiration date), then manually include it in the repository secrets:

https://particule.io/en/blog/cicd-github-registry/

[slingamn]

Except that's obsolete? https://docs.github.com/en/packages/managing-github-packages-using-github-actions-workflows/publishing-and-installing-a-package-with-github-actions#upgrading-a-workflow-that-accesses-ghcrio

[slingamn]

I was able to pull and run ghcr.io/ergochat/ergo:master successfully on Ubuntu Impish. It doesn't work on Focal, probably due to the faccessat2(2) problem.