Move prepare into store
Move prepare into store

We don't ever really need to prepare without doing storing, or storing
without preparing. So we make this one task. Plus they don't have output
leading to issues with tracking completion status.

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