Gracefully handle CI lint errors in artifacts section

If an artifacts section is included in the CI lint as an array instead of a Hash, users would see 500 errors when linting the file. Even though we separate validation that checks the type, this validation doesn't halt other validations from running. Since expose_as_present? is called inside a validation, we need to perform a redundant check to ensure the right type.

Closes #194069 (closed)