normalize to float in NanoBEIREvaluator, InformationRetrievalEvaluato…

…r, MSEEvaluator (UKPLab#3096)

sentence_transformers/evaluation/SentenceEvaluator.py

@@ -57,7 +57,7 @@ def __call__(
     def prefix_name_to_metrics(self, metrics: dict[str, float], name: str) -> dict[str, float]:
         if not name:
             return metrics
-        metrics = {name + "_" + key: value for key, value in metrics.items()}
+        metrics = {name + "_" + key: float(value) for key, value in metrics.items()}
         if hasattr(self, "primary_metric") and not self.primary_metric.startswith(name + "_"):
             self.primary_metric = name + "_" + self.primary_metric
         return metrics