[CI/Build][Intel] Enable benchmarks on Intel Gaudi 3 runner

[jakub-sochacki]

• Add linux.hpu.gaudi3.8 runner to benchmark matrix (placeholder)
• Create test-[throughput | latency | serving]-hpu.json files with benchmark configurations
• Add gaudi3 to default runners list in workflow dispatch
• Implement HPU device detection using hl-smi command
• Add HPU-specific Docker image suffix (-hpu)
• Add special commit selection for HPU that queries vllm-gaudi history
• Clone vllm-gaudi vllm/last-good-commit-for-vllm-gaudi branch to get compatibility history (N most recent VLLM_STABLE_COMMIT updates)
• Search through commit history to find most recent vLLM version with existing Docker image built by CI

The commit selection mechanism solves the race condition where VLLM_STABLE_COMMIT might change between CI image builds and benchmark runs (every 12 hours), ensuring benchmarks always find an existing compatible Docker image.