gh-35080: Use the Docker images published on ghcr.io without 'docker' in the name
    
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### 📚 Description

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Step 2 of the rename done in #35079.
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Step 2 make sure that multi-stage workflows and devcontainers use the
most current image, not the last image before the migration.

The "build" and "build-doc" workflows will be updated in a 3rd (and
final) step.
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### ⌛ Dependencies
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This should only be merged when the images with the new names have been
pushed.
    
URL: #35080
Reported by: Matthias Köppe
Reviewer(s): Dima Pasechnik

Author: Release Manager

.devcontainer/portability-Dockerfile

@@ -5,4 +5,4 @@ ARG SYSTEM_FACTOR="ubuntu-jammy"
 ARG PACKAGE_FACTOR="standard"
 ARG DOCKER_TARGET="with-system-packages"
 ARG DOCKER_TAG="dev"
-FROM ghcr.io/sagemath/sage/sage-docker-${SYSTEM_FACTOR}-${PACKAGE_FACTOR}-${DOCKER_TARGET}:${DOCKER_TAG}
+FROM ghcr.io/sagemath/sage/sage-${SYSTEM_FACTOR}-${PACKAGE_FACTOR}-${DOCKER_TARGET}:${DOCKER_TAG}

src/doc/en/developer/portability_testing.rst

@@ -651,7 +651,7 @@ packages instead of all of Sage, for example::
   [mkoeppe@sage sage]$ tox -e docker-centos-8-standard -- ratpoints
 
 If the build succeeds, this will create a new image named
-``sage-docker-centos-8-standard-with-targets:9.1.beta9-431-gca4b5b2f33-dirty``,
+``sage-centos-8-standard-with-targets:9.1.beta9-431-gca4b5b2f33-dirty``,
 where
 
 - the image name is derived from the tox environment name and the
@@ -676,22 +676,22 @@ the one just after running the ``configure`` script (``configured``)::
   Step 109/109 : RUN yum install -y zlib-devel || echo "(ignoring error)"
   ...
   Successfully built 4bb14c3d5646
-  Successfully tagged sage-docker-centos-8-standard-with-system-packages:9.1.beta9-435-g861ba33bbc-dirty
+  Successfully tagged sage-centos-8-standard-with-system-packages:9.1.beta9-435-g861ba33bbc-dirty
   Sending build context to Docker daemon ...
   ...
-  Successfully tagged sage-docker-centos-8-standard-configured:9.1.beta9-435-g861ba33bbc-dirty
+  Successfully tagged sage-centos-8-standard-configured:9.1.beta9-435-g861ba33bbc-dirty
   ...
   Sending build context to Docker daemon ...
   ...
-  Successfully tagged sage-docker-centos-8-standard-with-targets:9.1.beta9-435-g861ba33bbc-dirty
+  Successfully tagged sage-centos-8-standard-with-targets:9.1.beta9-435-g861ba33bbc-dirty
 
 Let's verify that the images are available::
 
   (base) egret:~/s/sage/sage-rebasing/worktree-algebraic-2018-spring (mkoeppe *$%>)$ docker images | head
   REPOSITORY                                                TAG                               IMAGE ID
-  sage-docker-centos-8-standard-with-targets                9.1.beta9-435-g861ba33bbc-dirty   7ecfa86fceab
-  sage-docker-centos-8-standard-configured                  9.1.beta9-435-g861ba33bbc-dirty   4314929e2b4c
-  sage-docker-centos-8-standard-with-system-packages        9.1.beta9-435-g861ba33bbc-dirty   4bb14c3d5646
+  sage-centos-8-standard-with-targets                9.1.beta9-435-g861ba33bbc-dirty   7ecfa86fceab
+  sage-centos-8-standard-configured                  9.1.beta9-435-g861ba33bbc-dirty   4314929e2b4c
+  sage-centos-8-standard-with-system-packages        9.1.beta9-435-g861ba33bbc-dirty   4bb14c3d5646
   ...
 
 
@@ -1082,8 +1082,8 @@ where you replace the token by your token, of course, and
 
 Now you can pull the image and run it::
 
-  $ docker pull ghcr.io/YOUR-GITHUB-USERNAME/sage/sage-docker-fedora-31-standard-configured:f4bd671
-  $ docker run -it ghcr.io/YOUR-GITHUB-USERNAME/sage/sage-docker-fedora-31-standard-configured:f4bd671 bash
+  $ docker pull ghcr.io/YOUR-GITHUB-USERNAME/sage/sage-fedora-31-standard-configured:f4bd671
+  $ docker run -it ghcr.io/YOUR-GITHUB-USERNAME/sage/sage-fedora-31-standard-configured:f4bd671 bash
 
 
 Using our pre-built Docker images published on ghcr.io
@@ -1101,19 +1101,19 @@ the build logs for a given platform.
 The image version corresponding to the latest development release
 receives the additional Docker tag ``dev``, see for example the Docker
 image for the platform `ubuntu-focal-standard
-<https://github.com/sagemath/sage/pkgs/container/sage%2Fsage-docker-ubuntu-focal-standard-with-targets-optional>`_. Thus,
+<https://github.com/sagemath/sage/pkgs/container/sage%2Fsage-ubuntu-focal-standard-with-targets-optional>`_. Thus,
 for example, the following command will work::
 
-  $ docker run -it ghcr.io/sagemath/sage/sage-docker-ubuntu-focal-standard-with-targets-optional:dev bash
-  Unable to find image 'ghcr.io/sagemath/sage/sage-docker-ubuntu-focal-standard-with-targets-optional:dev' locally
-  dev: Pulling from sagemath/sage/sage-docker-ubuntu-focal-standard-with-targets-optional
+  $ docker run -it ghcr.io/sagemath/sage/sage-ubuntu-focal-standard-with-targets-optional:dev bash
+  Unable to find image 'ghcr.io/sagemath/sage/sage-ubuntu-focal-standard-with-targets-optional:dev' locally
+  dev: Pulling from sagemath/sage/sage-ubuntu-focal-standard-with-targets-optional
   d5fd17ec1767: Already exists
   67586203f0c7: Pull complete
   b63c529f4777: Pull complete
   ...
   159775d1a3d2: Pull complete
   Digest: sha256:e6ba5e12f59c6c4668692ef4cfe4ae5f242556482664fb347bf260f32bf8e698
-  Status: Downloaded newer image for ghcr.io/sagemath/sage/sage-docker-ubuntu-focal-standard-with-targets-optional:dev
+  Status: Downloaded newer image for ghcr.io/sagemath/sage/sage-ubuntu-focal-standard-with-targets-optional:dev
   root@8055a7ba0607:/sage# ./sage
   ┌────────────────────────────────────────────────────────────────────┐
   │ SageMath version 9.6, Release Date: 2022-05-15                     │
@@ -1127,7 +1127,7 @@ contain a copy of the source tree and the full logs of the build and
 test.
 
 Also `smaller images corresponding to earlier build stages
-<https://github.com/orgs/sagemath/packages?tab=packages&q=sage-docker-debian-bullseye-standard>`_
+<https://github.com/orgs/sagemath/packages?tab=packages&q=sage-debian-bullseye-standard>`_
 are available:
 
  * ``-with-system-packages`` provides a system installation with

tox.ini

@@ -462,7 +462,7 @@ setenv =
     # Resulting full image:tag name
     #
     docker:             FULL_BASE_IMAGE_AND_TAG={env:ARCH_IMAGE_PREFIX:}{env:BASE_IMAGE}{env:ARCH_IMAGE_SUFFIX:}:{env:ARCH_TAG_PREFIX:}{env:BASE_TAG}{env:ARCH_TAG_SUFFIX:}
-    docker-incremental: FULL_BASE_IMAGE_AND_TAG={env:FROM_DOCKER_REPOSITORY:ghcr.io/sagemath/sage/}sage-$(echo {envname} | sed 's/-incremental//')-{env:FROM_DOCKER_TARGET:with-targets}:{env:FROM_DOCKER_TAG:dev}
+    docker-incremental: FULL_BASE_IMAGE_AND_TAG={env:FROM_DOCKER_REPOSITORY:ghcr.io/sagemath/sage/}sage-$(echo {envname} | sed -E "s/(docker-|-incremental)//g")-{env:FROM_DOCKER_TARGET:with-targets}:{env:FROM_DOCKER_TAG:dev}
     docker-incremental: SKIP_SYSTEM_PKG_INSTALL=yes
     #
     docker-nobootstrap: BOOTSTRAP=./bootstrap -D