Upgrade pip used in the pipeline
Python 3.12 has no distutils anymore, which is used by the older pip.
Broken rawhide pipeline: https://gitlab.com/cki-project/pipeline-definition/-/jobs/4611324961
This prevents the builds of newer rawhide builder images.
pip is version-locked in the pipeline because the dependency resolution algorithm changes are evil
AC:
- upgrade pipeline to newer pip without distutils