Define that we mark some tests as slow
Define that we mark some tests as slow

This may be useful as there are some really slow tests that we may skip
in a CI context.

RNAcentral/rnacentral-import-pipeline,RNAcentral/rnacentral-import-pipeline,RNAcentral/rnacentral-import-pipeline,RNAcentral/rnacentral-import-pipeline