JUnit report

It would make sense to create a JUnit report in the validation script that lists which repositories we've tested and whether they worked.

It should show the repository test as failed if there is a fatal problem that will make the repository unusable.

It should produce something that shows up as a warning if the repository has a non-fatal problem that does not make the repository unusable but that could become problematic in the future (e.g., deprecated key algorithms, or keys that are about to expire)

We can then upload the JUnit report to salsa and make checking/fixing problems in repositories much easier.