deployment: update docker images of dependencies

[mdonadoni]

We should upgrade the docker images we are using for external dependencies, such as:

• Jupyter notebooks (checkt that periodic closure of inactive notebooks still works!)
• Redis
• RabbitMQ

We should also update the prefetch-images.sh file accordingly.

For long term, we should decide how often to update them and how to remember to do so, for example by adding a new action to the release checklist.