fix: add logging for RetrievalEvaluator NaN values for similarity scores

[KennethEnevoldsen]

Fixes #1389

Ran through tests but couldn't find a case where it was actually used. It might be a thing we can simply remove.

Checklist

• Run tests locally to make sure nothing is broken using make test.
• Run the formatter to format the code using make lint.

[KennethEnevoldsen]

@orionw or @Muennighoff will merge this in but would love to remove the -1 transformation if possible

[orionw]

I’m not aware of when it would happen, I think it was there when I started using MTEB. I assume like guessed in #1389 it’s for overflow or something.

Perhaps @Muennighoff may know more.

[Muennighoff]

Yeah I'm also not sure, maybe when embeddings are NaN, but then that's a problem with the model and we probably shouldn't work around that 🤔 We can also remove it and wait until someone reports an issue with it

[KennethEnevoldsen]

removing them in #1444