Run EOS5 CI every night
We need to run EOS 5 CI on the master branch every day during the night so that we can catch possible regressions.
This requires a dedicated branch as it is not very simple to trigger a manual job using schedules.
Xrootd 5 builds based on the CI variable approach will be simpler to address but there is really no point in running the full pipeline for EOS5 as it is isolated from CTA build jobs.