remove unused fn

Author: a-r-r-o-w

src/diffusers/models/transformers/transformer_ltx.py

@@ -412,16 +412,6 @@ def forward(
 
         for block in self.transformer_blocks:
             if torch.is_grad_enabled() and self.gradient_checkpointing:
-
-                def create_custom_forward(module, return_dict=None):
-                    def custom_forward(*inputs):
-                        if return_dict is not None:
-                            return module(*inputs, return_dict=return_dict)
-                        else:
-                            return module(*inputs)
-
-                    return custom_forward
-
                 hidden_states = self._gradient_checkpointing_func(
                     block,
                     hidden_states,