#3132 Note on ZE_AFFINITY_MASK vs /sys/class/drm Enumeration in sycl/setup_intel.py

Description

On a mixed 3-GPU system (0: Arc Pro B50 at 48:00.0, 1: Arc Pro B70 at 62:00.0, 2: Arc Pro B70 at e4:00.0), setup_intel.py enumerates GPUs via sysfs (/sys/class/drm), which ignores ZE_AFFINITY_MASK. Passing --gpus 1,2 (without ZE_AFFINITY_MASK) works cleanly.