format pod_block.py

delete one line

Author: annaivagnes

pina/model/block/pod_block.py

@@ -163,7 +163,6 @@ def _fit_pod(self, X, randomized):
         self._basis = u.T
         self._singular_values = s
 
-
     def forward(self, X):
         """
         The forward pass of the POD layer.