fix: description vectors error

Author: Darinochka

autointent/modules/scoring/_description/description.py

@@ -174,6 +174,10 @@ def predict(self, utterances: list[str]) -> NDArray[np.float64]:
                 error_text = "Cross encoder is not initialized. Call fit() before predict()."
                 raise RuntimeError(error_text)
 
+            if self._description_texts is None:
+                error_text = "Description texts are not initialized. Call fit() before predict()."
+                raise RuntimeError(error_text)
+
             pairs = [(utterance, description) for utterance in utterances for description in self._description_texts]
 
             scores = self._cross_encoder.predict(pairs)