[EPIC] multi-image/version pipelines

[jdries]

We now support running batch jobs with multiple images, but do not have a way to keep them up to date.
Some design considerations:

• to enable transitioning UDF's between python 3.8 and 3.11, users will need up to date versions of both images
• in integration testing, it makes sense to run some batch job tests with both versions, but not necessarily all of them
• synchronous calls remain on one fixed version
• unit tests for openeo-geopyspark-driver: run against both versions
• image building pipelines may need separation from integrationtests: now we always build a full new image for each tests
• artifactory has issues dealing with too many dev images, we don't want to make this even worse. Images with failed tests should not be retained long, while images with successful tests are often more useful to keep longer. (https://github.com/eu-cdse/openeo-cdse-infra/issues/274)

[soxofaan]

Related to desire to drop Python 3.8 support in openeo python client (because quite some relevant libraries already stopped caring about python 3.8, e.g. geopandas, pystac, ...):

• Drop support for Python 3.8 openeo-python-client#717

[jdries]

When we continuously build new images, we can continue with this one:
Open-EO/openeo-geopyspark-driver#752

[jdries]

There's now a separate jenkins pipeline to trigger building and testing for python 3.11.
It uses same git branch, so the jenkinsfile itself is made to be generic.
https://jenkins.vgt.vito.be/job/openEO/job/openeo-integrationtests-python311/