update afrixnli tasks

lm_eval/tasks/afrixnli/en-direct/utils.py

+from sklearn.metrics import f1_score
+
+
+def doc_to_target(doc):
+    replacements = {
+        0: 'True',
+        1: 'Neither',
+        2: 'False'
+    }
+    return replacements[doc["label"]]
+
+
+def weighted_f1_score(items):
+    unzipped_list = list(zip(*items))
+    golds = unzipped_list[0]
+    preds = unzipped_list[1]
+    fscore = f1_score(golds, preds, average="weighted")
+    return fscore