Reduce img size in dummy_inputs for FLUX (#1070)

* Reduce img size in dummy_inputs for FLUX

* change dims in function signature

* Update optimum/exporters/openvino/model_configs.py

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Co-authored-by: Ilyas Moutawwakil <57442720+IlyasMoutawwakil@users.noreply.github.com>

Author: mvafin

optimum/exporters/openvino/model_configs.py

@@ -1804,8 +1804,9 @@ def __init__(
         normalized_config: NormalizedVisionConfig,
         batch_size: int = DEFAULT_DUMMY_SHAPES["batch_size"],
         num_channels: int = DEFAULT_DUMMY_SHAPES["num_channels"],
-        width: int = DEFAULT_DUMMY_SHAPES["width"],
-        height: int = DEFAULT_DUMMY_SHAPES["height"],
+        width: int = DEFAULT_DUMMY_SHAPES["width"] // 4,
+        height: int = DEFAULT_DUMMY_SHAPES["height"] // 4,
+        # Reduce img shape by 4 for FLUX to reduce memory usage on conversion
         **kwargs,
     ):
         super().__init__(task, normalized_config, batch_size, num_channels, width, height, **kwargs)