Skip the ext initializer logic when dynamic shapes are used

[intbf]

When dynamic shapes are used the model proto might change and invalidate the offsets for ext initializers

Description

During the investigation I noticed that offsets created for EXT initializers are updated/overridden when dynamic shapes are used.

We create model_proto from fused nodes in backend_manager (call to GetModelProtoFromFusedNode)
But then we call BackendManager::Compute, and it requires dynamic backend: (need_dynamic_backend is true)

Data breakpoints on the memory offets from initializers, are hit in BackendManager::ReWriteInputShapeInfo (somewhere down into model_copy->ParseFromString(proto_str);)

The model proto changes, and it's not reliable to use it with open vino

Later when OV tries to get tensor data via TensorExternalData::load_external_mem_data() it crashes because pointers/offsets might be invalidated

Motivation and Context

https://jira.devtools.intel.com/browse/CVS-174804

[Copilot]

Pull Request Overview

This PR modifies the OpenVINO backend manager to skip external initializer logic when dynamic shapes are detected. The change prevents potential issues where model proto changes could invalidate offset calculations for external initializers.

• Moves the dynamic shape detection logic earlier in the constructor
• Skips external initializer processing when dynamic input shapes are present

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[Copilot]

Pull Request Overview

Copilot reviewed 1 out of 1 changed files in this pull request and generated 1 comment.

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[MayureshV1]

LGTM !