[core] Refactor of gradient_checkpointing (#27020)

* v1

* fix

* remove `create_custom_forward`

* fixup

* fixup

* add test and fix all failing GC tests

* remove all remaining `create_custom_forward` methods

* fix idefics bug

* fixup

* replace with `__call__`

* add comment

* quality

src/transformers/models/sam/modeling_sam.py

@@ -1042,15 +1042,8 @@ class SamVisionEncoder(nn.Module):
                 all_hidden_states = all_hidden_states + (hidden_states,)
 
             if self.gradient_checkpointing and self.training:
-
-                def create_custom_forward(module):
-                    def custom_forward(*inputs):
-                        return module(*inputs, output_attentions)
-
-                    return custom_forward
-
-                layer_outputs = torch.utils.checkpoint.checkpoint(
-                    create_custom_forward(layer_module),
+                layer_outputs = self.gradient_checkpointing_func(
+                    layer_module.__call__,
                     hidden_states,
                 )
             else: