fix: add target size check

fedot/core/operations/evaluation/operation_implementations/models/boostings_implementations.py

@@ -91,10 +91,10 @@ def plot_feature_importance(self, importance_type='weight'):
     @staticmethod
     def convert_to_dataframe(data: Optional[InputData], identify_cats: bool):
         dataframe = pd.DataFrame(data=data.features)
-        if data.target is not None:
+        if data.target is not None and data.target.size > 0:
             dataframe['target'] = np.ravel(data.target)
         else:
-            # TODO: temp workaround in case data.target is set to None intentionally
+            # TODO: temp workaround in case data.target is set to None or an empty sequence intentionally
             #  for test.integration.models.test_model.check_predict_correct
             dataframe['target'] = np.zeros(len(data.features))
 
@@ -236,10 +236,10 @@ def set_eval_metric(n_classes):
     @staticmethod
     def convert_to_dataframe(data: Optional[InputData], identify_cats: bool):
         dataframe = pd.DataFrame(data=data.features, columns=data.features_names)
-        if data.target is not None:
+        if data.target is not None and data.target.size > 0:
             dataframe['target'] = np.ravel(data.target)
         else:
-            # TODO: temp workaround in case data.target is set to None intentionally
+            # TODO: temp workaround in case data.target is set to None or an empty sequence intentionally
             #  for test.integration.models.test_model.check_predict_correct
             dataframe['target'] = np.zeros(len(data.features))