refactor: setting pred split to sole dataset

Signed-off-by: Kin Long Kelvin Lee <[email protected]>

matsciml/lightning/data_utils.py

@@ -259,6 +259,9 @@ def setup(self, stage: str | None = None) -> None:
                     f"Prediction split provided, but not found: {pred_split_path}"
                 )
             dset = self._make_dataset(pred_split_path, self.dataset)
+            # assumes that if we're providing a predict set, we're not going
+            # to be doing training in the same run
+            self.dataset = dset
             splits["pred"] = dset
         # the last case assumes only the dataset is passed, we will treat it as train
         if len(splits) == 0: