Allow read permissions on `openjdkXX-pipeline` jobs

[sxa]

I don't recall how we ended up with this being non-public. I can only think it would be if we had builds with artifacts that didn't have beta identifiers on them, but since the openjdkXX-pipeline jobs pull their artifacts from the (public) platform specific pipelines I can't see why that would be an issue.

This issue is to analyse whether there is any current reason for those top level pipelines to be restricted access.