fix label shape for lss regression

Author: AnFreTh

mambular/base_models/lightning_wrapper.py

@@ -126,7 +126,7 @@ def compute_loss(self, predictions, y_true):
             Computed loss.
         """
         if self.lss:
-            return self.family.compute_loss(predictions, y_true)
+            return self.family.compute_loss(predictions, y_true.squeeze(-1))
         else:
             loss = self.loss_fct(predictions, y_true)
             return loss