CVS-178227 : Fix tensor data access for OpenVINO 2026.0 compatibility

[ankitm3k]

Description

Fixes OpenVINO EP compatibility with OpenVINO 2026.0 by updating tensor data access patterns to use raw untyped data() accessor instead of templated data<T>().

Motivation & Context

OpenVINO 2026.0 introduced two breaking changes for ov::Tensor data access:

1. Read-only memory-mapped tensors: Memory-mapped tensors from ov::read_tensor_data() now use ReadOnlyViewTensor which throws when calling the templated data<T>() method.

2. Sub-byte element types (i4/u4): Tensors with INT4 or UINT4 element types fail the is_pointer_representable check when calling data<uint8_t>().

Resolves Runtime Errors

Error 1 - Read-only tensor access:

Exception during initialization: Exception from src/core/src/runtime/tensor.cpp:117:
Exception from src/inference/src/dev/make_tensor.cpp:178:
Can not access non-const pointer use e.g. 'static_cast<const ov::Tensor&>.data(element_type)'

Error 2 - Sub-byte type access:

Exception during initialization: Exception from src/core/src/runtime/tensor.cpp:117:
Tensor data with element type i4, is not representable as pointer to u8

Changes

Updated tensor data access in 3 files to use raw untyped data() accessor:

File	Description
ov_shared_context.cc	Memory-mapped weights and host tensor access for sub-byte types
ov_bin_manager.cc	Binary cache stream buffer and mapped blob access
ov_allocator.cc	NPU host tensor allocation

Before:

const_cast<char*>(tensor.data<char>());

After:

const_cast<void*>(static_cast<const ov::Tensor&>(tensor).data())

The untyped data() accessor:

• Works on read-only tensors when accessed via const reference
• Bypasses is_pointer_representable check for sub-byte types (i4/u4)
• Follows the pattern used in OpenVINO's own codebase (see ov::op::v0::Constant constructor)

JIRA: https://jira.devtools.intel.com/browse/CVS-178227