fix: z_score correct order in zuko (#1492)

Co-authored-by: Nastya Krouglova <nastyakrouglova@webauth446.uni-tuebingen.de>

Author: anastasiakrouglova

sbi/neural_nets/net_builders/flow.py

@@ -1068,8 +1068,8 @@ def build_zuko_flow(
         z_score_x_bool, structured_x = z_score_parser(z_score_x)
         if z_score_x_bool:
             transform = (
-                transform,
                 standardizing_transform_zuko(batch_x, structured_x),
+                transform,
             )
 
         z_score_y_bool, structured_y = z_score_parser(z_score_y)
@@ -1087,8 +1087,8 @@ def build_zuko_flow(
         z_score_x_bool, structured_x = z_score_parser(z_score_x)
         if z_score_x_bool:
             transforms = (
-                *transforms,
                 standardizing_transform_zuko(batch_x, structured_x),
+                *transforms,
             )
 
         z_score_y_bool, structured_y = z_score_parser(z_score_y)