These docker images are built by the portability CI workflows for Linux.
However, refactoring of the workflow had broken the upload to docker.pkg.github.com. (Although the login to docker.pkg.github.com succeeds, the push fails with no basic auth credentials - see https://github.com/mkoeppe/sage/runs/1414148202?check_suite_focus=true)
CC: @kliem @dimpase @tobiasdiez
Component: porting
Author: Matthias Koeppe
Branch/Commit: 21afe51
Reviewer: Dima Pasechnik
Issue created by migration from https://trac.sagemath.org/ticket/30933