Fix 2 CPU failures in cpu-torch-latest

[jinyouzhi]

Follow up #8381 @delock
Fix CPU CI failures in https://github.com/deepspeedai/DeepSpeed/actions/runs/35675316100/job/106580600974?pr=8381

FAILED unit/inference/quantization/test_intX_quantization.py::TestQuantizedInt::test_half_int8_quantization 
FAILED unit/checkpoint/test_convert_checkpoint.py::TestCheckpointConvert::test_convert_zero_checkpoint_to_fp32_state_dict 

[hwchen2017]

Looks like adding a per-test  @pytest.mark.skipif(...)  to  test_half_int8_quantization  would address the failure while preserving the supported CPU cases.

[jinyouzhi]

Looks like adding a per-test  @pytest.mark.skipif(...)  to  test_half_int8_quantization  would address the failure while preserving the supported CPU cases.

Good advice! pushed.