Fix pions
There are currently no pipelines.
To run a merge request pipeline, the jobs in the CI/CD configuration file must be configured to run in merge request pipelines and you must have sufficient permissions in the source project.
Reverted generating pi0s in the pions.cxx file back to generating pi+s, as it was initially intended to.
To run a merge request pipeline, the jobs in the CI/CD configuration file must be configured to run in merge request pipelines and you must have sufficient permissions in the source project.