Disable DIV with broadcast on OpenVINO GPU backend

[zhaixuejun1993]

This pull request makes targeted improvements to the dynamic dimension handling and operator support logic in the OpenVINO backend of the codebase. The main changes focus on making error handling more robust in the decoder and adding better support for division operations, especially when broadcasting is involved on GPU devices.

Dynamic dimension handling improvements:

• Replaced assertions with warnings in GgmlOvDecoder::compute_node_dynamic_dims() to prevent hard failures when dynamic dimension mismatches are detected, instead setting the dynamic dimension to -1 and logging a warning.
• Added a warning and fallback for cases where the dynamic dimension for a CONT node cannot be uniquely determined, instead of asserting and halting execution.

Operator support enhancements:

• Updated is_op_unsupported_case() to mark division operations (GGML_OP_DIV) as unsupported when broadcasting is required and the device is GPU, due to known issues with fused GPU kernels producing invalid results. This prevents problematic DIV operations from running on GPU until the kernel is reliable.## Overview

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