Remove citation.tsv from the test resources, and use the production file instead

[pkiraly]

@scolapasta reported>

This PR: https://github.com/IQSS/dataverse/pull/6921/files

added a copy of citation.tsv. Is there a reason why it didn't just use the one that ships with Dataverse? (I am making a change to citation.tsv and will make it in both places for now, BUT that's not ideal. If it's not needed to be separate, would you be willing to make a small PR to remove the duplicate and use the standard one? Thanks!