feat(setup.py): increase cubicweb max version to 3.31.x

Hello dear contributors,

This is an auto generated MR to set a higher born for the cubicweb dependency and automatically increase it on release if the test pass. You can find more information here: cubicweb/cubicweb#387 (closed)

Kind regards,

added To Review label

enabled an automatic merge when the pipeline for 98d6afd14adb succeeds

merged

requested review from @fferry