use a generator for unpacking in a mem efficient way

src/nemos/basis/_transformer_basis.py

@@ -99,13 +99,13 @@ def _unpack_inputs(self, X: FeatureMatrix) -> List:
 
         """
         n_samples = X.shape[0]
-        out = [
+        out = (
             np.reshape(X[:, cc : cc + n_input], (n_samples, *bas._input_shape_))
             for i, (bas, n_input) in enumerate(
                 zip(self._list_components(), self._n_basis_input_)
             )
             for cc in [sum(self._n_basis_input_[:i])]
-        ]
+        )
         return out
 
     def fit(self, X: FeatureMatrix, y=None):