Adding FarsTail (Persian) for Pair Classification

[wissam-sib]

Still missing some languages in Pair Classification so adding this Persian dataset.

• [x] I have tested that the dataset runs with the mteb package.
• [x] I have run the following models on the task (adding the results to the pr). These can be run using the mteb -m {model_name} -t {task_name} command.
  • [x] sentence-transformers/paraphrase-multilingual-MiniLM-L12-v2
  • [x] intfloat/multilingual-e5-small
• [x] I have checked that the performance is neither trivial (both models gain close to perfect scores) nor random (both models gain close to random scores).
• [x] I have filled out the metadata object in the dataset file (find documentation on it here).
• [x] Run tests locally to make sure nothing is broken using make test.
• [x] Run the formatter to format the code using make lint.
• [ ] I have added points for my submission to the points folder using the PR number as the filename (e.g. 438.jsonl).

[wissam-sib]

Code changes LGTM. I wonder if the similar scores by both models is a potential issue?

I tested with a Persian embedding model and it made a difference. However, I decided to switch to another label available in the dataset (entailment/contradiction) which leads to larger variability.