Generate partitioning script properly

lib/modules/partition.nix

@@ -231,7 +231,13 @@
           };
         };
 
-        script = config.partition.os.script;
+        script =
+          let
+            inherit (config.partition)
+              os
+              disks
+            ;
+          in lib.strings.concatLines (builtins.map (_: _.script) ([os] ++ (builtins.attrValues disks)));
       };
     };
   }