fix: Pass NVML CC settings by reference in release/1.2.1

TensorRT-LLM 1.2.1 can segfault during worker initialization with nvidia-ml-py==13.610.43. On H200 NVL with driver 610.57.04, the failure occurs after model weights load and before the HTTP server becomes ready, in both GPU CC-off and TDX/GPU CC-on deployments.

The release passes c_nvmlSystemConfComputeSettings_v1_t by value to nvmlSystemGetConfComputeSettings. The pynvml wrapper forwards the argument to the native NVML function, which expects a pointer. Passing ctypes.byref(cc_settings) resolves the argument mismatch.

The pointer-based call is already present on main through #16850. The proposed release/1.2.1 backport applies this correction while preserving the release's existing CC/NVLE classification. All four added regression cases fail against the original source and pass with the correction.

Compare the release/1.2.1 NVML call with the pointer-based call already present on main through #16850, focusing on pynvml's handling of c_nvmlSystemConfComputeSettings_v1_t. Apply the backport while preserving the release's existing CC/NVLE classification, then run the four added regression cases and confirm they fail before and pass after the correction.