Following #16582 and #16623, there are some potential improvements that could be made to the new CI setup:

• It'd be handy if the Docker containers were named. amd64_qt is more useful than peaceful_rubin once there are a bunch floating around. Done in test: set a name for CI Docker containers #18081.
• Maybe we could stop (although not destroy) containers automatically after successful completion of the tests?
• The ci is generally assuming the the folder is a fresh git clone. If needed, that can be changed later on, but better not part of this pull.