Release 12.3

> How to

During release

1. Push the new version which will create a Docker image with the stable version:

   bundle exec rake "release:single[X.Y]"

2. Make sure the proper milestone is assigned to this MR and:

   1. Edit content/_data/versions.yaml and rotate the versions.
   2. Edit content/404.html and add the old removed version to the list of redirects at the bottom of the file.
   3. Edit dockerfiles/Dockerfile.archives and add the new version.
   4. Edit Dockerfile.master and rotate the versions.

3. (Optional) If there are changes in the stable branches of the docs after the release version Docker image was created, rerun the release version pipeline.

Before merge

On the 22nd, before merging this and right after a scheduled pipeline has run:

1. Bump the dropdown versions for all online versions:

   bundle exec rake release:dropdowns

2. Merge all merge requests created from the above command.
3. Once all above pipelines are green, it's time to merge this MR.
4. (Optional) Manually run the scheduled pipeline.