[TorchFX][Conformance test] Migration to torch.export.export (#2990)

### Changes

* tests/post_training/pipelines/image_classification_torchvision.py
supports both `capture_pre_autograd_model` and
`torch.export.export(...).module()` export paths
* Micro fix in NNCFGraph

### Reason for changes

* capture_pre_autograd_graph introduces accuracy drop for the swin_v2_s
model (Improvement: Metric value is better than reference 0.836 >
0.8296)
* Incorrect constant collection fails on models exported via
`torch.export.export(...).module()`

### Related tickets

#2766 

### Tests

post_training_quantization/490/

nncf/experimental/torch/fx/nncf_graph_builder.py

@@ -185,7 +185,7 @@ def get_edge_params(
         output_port_id = 0
         tensor_shape = None
         if source_node.op in ("get_attr",):
-            tensor_shape = tuple(getattr(model, source_node.target).shape)
+            tensor_shape = tuple(get_tensor_constant_from_node(source_node, model).shape)
         elif "val" in source_node.meta:
             if source_nncf_node.metatype is om.PTBatchNormMetatype:
                 tensor = source_node.meta["val"][0]

tests/post_training/data/ptq_reference_data.yaml

@@ -57,7 +57,7 @@ torchvision/swin_v2_s_backend_FP32:
 torchvision/swin_v2_s_backend_OV:
   metric_value: 0.83638
 torchvision/swin_v2_s_backend_FX_TORCH:
-  metric_value: 0.8296
+  metric_value: 0.8360
 timm/crossvit_9_240_backend_CUDA_TORCH:
   metric_value: 0.689
 timm/crossvit_9_240_backend_FP32:

tests/post_training/pipelines/image_classification_torchvision.py

@@ -9,6 +9,9 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.
 
+from dataclasses import dataclass
+from typing import Any, Callable, Tuple
+
 import numpy as np
 import onnx
 import openvino as ov
@@ -22,29 +25,45 @@
 from tests.post_training.pipelines.image_classification_base import ImageClassificationBase
 
 
+def _capture_pre_autograd_module(model: torch.nn.Module, args: Tuple[Any, ...]) -> torch.fx.GraphModule:
+    return capture_pre_autograd_graph(model, args)
+
+
+def _export_graph_module(model: torch.nn.Module, args: Tuple[Any, ...]) -> torch.fx.GraphModule:
+    return torch.export.export(model, args).module()
+
+
+@dataclass
+class VisionModelParams:
+    weights: models.WeightsEnum
+    export_fn: Callable[[torch.nn.Module, Tuple[Any, ...]], torch.fx.GraphModule]
+
+
 class ImageClassificationTorchvision(ImageClassificationBase):
     """Pipeline for Image Classification model from torchvision repository"""
 
-    models_vs_imagenet_weights = {
-        models.resnet18: models.ResNet18_Weights.DEFAULT,
-        models.mobilenet_v3_small: models.MobileNet_V3_Small_Weights.DEFAULT,
-        models.vit_b_16: models.ViT_B_16_Weights.DEFAULT,
-        models.swin_v2_s: models.Swin_V2_S_Weights.DEFAULT,
+    models_vs_model_params = {
+        models.resnet18: VisionModelParams(models.ResNet18_Weights.DEFAULT, _capture_pre_autograd_module),
+        models.mobilenet_v3_small: VisionModelParams(
+            models.MobileNet_V3_Small_Weights.DEFAULT, _capture_pre_autograd_module
+        ),
+        models.vit_b_16: VisionModelParams(models.ViT_B_16_Weights.DEFAULT, _export_graph_module),
+        models.swin_v2_s: VisionModelParams(models.Swin_V2_S_Weights.DEFAULT, _export_graph_module),
     }
 
     def __init__(self, *args, **kwargs):
         super().__init__(*args, **kwargs)
-        self.model_weights: models.WeightsEnum = None
+        self.model_params: VisionModelParams = None
         self.input_name: str = None
 
     def prepare_model(self) -> None:
         model_cls = models.__dict__.get(self.model_id)
-        self.model_weights = self.models_vs_imagenet_weights[model_cls]
-        model = model_cls(weights=self.model_weights)
+        self.model_params = self.models_vs_model_params[model_cls]
+        model = model_cls(weights=self.model_params.weights)
         model.eval()
 
         default_input_size = [self.batch_size, 3, 224, 224]
-        self.dummy_tensor = self.model_weights.transforms()(torch.rand(default_input_size))
+        self.dummy_tensor = self.model_params.weights.transforms()(torch.rand(default_input_size))
         self.static_input_size = list(self.dummy_tensor.shape)
 
         self.input_size = self.static_input_size.copy()
@@ -54,7 +73,7 @@ def prepare_model(self) -> None:
         if self.backend == BackendType.FX_TORCH:
             with torch.no_grad():
                 with disable_patching():
-                    self.model = capture_pre_autograd_graph(model, (self.dummy_tensor,))
+                    self.model = self.model_params.export_fn(model, (self.dummy_tensor,))
 
         elif self.backend in PT_BACKENDS:
             self.model = model
@@ -103,7 +122,7 @@ def _dump_model_fp32(self) -> None:
             ov.serialize(self.model, self.fp32_model_dir / "model_fp32.xml")
 
     def prepare_preprocessor(self) -> None:
-        self.transform = self.model_weights.transforms()
+        self.transform = self.model_params.weights.transforms()
 
     def get_transform_calibration_fn(self):
         if self.backend in [BackendType.FX_TORCH] + PT_BACKENDS: