Deal with version bumps

[Zalfsten]

According to best practices this repo specifies the sha256 hashes of docker base images and python package versions in requirements.txt.
One version spec is missing, though: for the installed apk package in the docker image. This should be updated. But this is not that easy, because when it comes to python, the major and minor versions are also encoded in the package names. E.g.:

package name: python-3.12
package version: 3.12.1-r0

It's yet unclear how to deal with this.

Really important: we need to define a procedure to induce version bumps. Preferably this procedure should be fully automatic:

• figure out old version
• create a github merge request containing version upgrade
• automatically test the resulting image