[Bug] Intermitant failure of upload_csv route

[bh2smith]

More specifically, there seems to be an reliability issue with upload_csv endpoint. It sporadically fails in CI with {'error': 'An internal error occured'}.

The only thing I can think of at the moment is that CI calls the method from both python 3.8 and 3.11 simultaneously causing some sort of Lock error.

TODO lift skipped test from #84