fix: distance measure in non llm CR (#1787)

```python
from ragas import evaluate
from ragas.metrics import NonLLMContextRecall, NonLLMContextPrecisionWithReference
from ragas import SingleTurnSample, EvaluationDataset
from ragas.metrics._string import DistanceMeasure

sample = SingleTurnSample(
    retrieved_contexts=["Paris is the capital of France."], 
    reference_contexts=["Paris is the capital of France.", "The Eiffel Tower is one of the most famous landmarks in Paris."]
)
dataset = EvaluationDataset(samples=[sample, sample, sample])

scorer = NonLLMContextRecall()

result = evaluate(
    dataset,
    metrics=[scorer],
)

scorer.distance_measure = DistanceMeasure.JARO_WINKLER

result = evaluate(
    dataset,
    metrics=[scorer],
)```

Author: shahules786

src/ragas/metrics/_context_recall.py

@@ -8,7 +8,7 @@
 from pydantic import BaseModel
 
 from ragas.dataset_schema import SingleTurnSample
-from ragas.metrics._string import NonLLMStringSimilarity
+from ragas.metrics._string import DistanceMeasure, NonLLMStringSimilarity
 from ragas.metrics.base import (
     MetricOutputType,
     MetricType,
@@ -210,19 +210,23 @@ class NonLLMContextRecall(SingleTurnMetric):
         }
     )
     output_type: MetricOutputType = MetricOutputType.CONTINUOUS
-    distance_measure: SingleTurnMetric = field(
+    _distance_measure: SingleTurnMetric = field(
         default_factory=lambda: NonLLMStringSimilarity()
     )
     threshold: float = 0.5
 
-    def __post_init__(self):
-        if isinstance(self.distance_measure, MetricWithLLM):
-            raise ValueError(
-                "distance_measure must not be an instance of MetricWithLLM for NonLLMContextPrecisionWithReference"
-            )
-
     def init(self, run_config: RunConfig) -> None: ...
 
+    @property
+    def distance_measure(self) -> SingleTurnMetric:
+        return self._distance_measure
+
+    @distance_measure.setter
+    def distance_measure(self, distance_measure: DistanceMeasure) -> None:
+        self._distance_measure = NonLLMStringSimilarity(
+            distance_measure=distance_measure
+        )
+
     async def _single_turn_ascore(
         self, sample: SingleTurnSample, callbacks: Callbacks
     ) -> float: