WIP: Use ystream_* variables, but keep old unused ones for now

This would need to be split into a couple of MRs for the migrations:

• define the new variables in kpet-db, but don't use them: https://gitlab.com/cki-project/kpet-db/-/merge_requests/31
• enable the pipeline to pass the new variables: cki-project/pipeline-definition!918 (merged)
• use the new variables in kpet-db: https://gitlab.com/cki-project/kpet-db/-/merge_requests/32
• update bot message in pipeline-data: https://gitlab.cee.redhat.com/cki-project/deployment-all/-/merge_requests/167
• mark the vars as deprecated in cki-tools: cki-project/cki-tools!64 (merged)
• remove the old variables from all pipeline-data repos: https://gitlab.cee.redhat.com/cki-project/pipeline-data/-/merge_requests/31
• disable the old variables in the pipeline: cki-project/pipeline-definition!920 (merged)
• remove the old variables from kpet-db: https://gitlab.com/cki-project/kpet-db/-/merge_requests/35