chore: add forward method to hybrid model (#846)

src/concrete/ml/torch/hybrid_model.py

@@ -399,6 +399,19 @@ def _replace_modules(self):
             )
             setattr(parent_module, last, remote_module)
 
+    def forward(self, x: torch.Tensor, fhe: str = "disable") -> torch.Tensor:
+        """Forward pass of the hybrid model.
+
+        Args:
+            x (torch.Tensor): The input tensor.
+            fhe (str): The Fully Homomorphic Encryption (FHE) mode (default is "disable").
+
+        Returns:
+            torch.Tensor: The output tensor.
+        """
+        self.set_fhe_mode(fhe)
+        return self.model(x)
+
     def __call__(self, x: torch.Tensor, fhe: str = "disable") -> torch.Tensor:
         """Call method to run the model locally with a fhe mode.
 
@@ -409,9 +422,7 @@ def __call__(self, x: torch.Tensor, fhe: str = "disable") -> torch.Tensor:
         Returns:
             (torch.Tensor): The output tensor.
         """
-        self.set_fhe_mode(fhe)
-        x = self.model(x)
-        return x
+        return self.forward(x, fhe)
 
     @staticmethod
     def _get_module_by_name(model: nn.Module, name: str) -> Union[RemoteModule, nn.Module]: