Add evaluation results on the squad_v2 config and validation split of squad_v2

Beep boop, I am a bot from Hugging Face's automatic model evaluator 👋!\
Your model has been evaluated on the squad_v2 config and validation split of the [squad_v2](https://huggingface.co/datasets/squad_v2) dataset by

@anchal

, using the predictions stored [here](https://huggingface.co/datasets/autoevaluate/autoeval-eval-squad_v2-squad_v2-5d46e4-1992966290).\
Accept this pull request to see the results displayed on the [Hub leaderboard](https://huggingface.co/spaces/autoevaluate/leaderboards?dataset=squad_v2).\
Evaluate your model on more datasets [here](https://huggingface.co/spaces/autoevaluate/model-evaluator?dataset=squad_v2).

README.md

@@ -17,11 +17,11 @@ model-index:
     metrics:
     - name: Exact Match
       type: exact_match
-      value: 71.1517
+      value: 71.1542
       verified: true
     - name: F1
       type: f1
-      value: 74.6714
+      value: 74.6707
       verified: true
 ---