[BugFix] Skip the Q component for QKVParallelLinear in the case of QKVCrossParallelLinear since its width is 0 (#22369)

Signed-off-by: sstamenk <[email protected]>

Author: sstamenk

vllm/model_executor/layers/quantization/utils/w8a8_utils.py

@@ -121,6 +121,9 @@ def requantize_with_max_scale(
     if unfused_module_in_checkpoint:
         start = 0
         for idx, logical_width in enumerate(logical_widths):
+            # Skip any component with zero width.
+            if logical_width == 0:
+                continue
             end = start + logical_width
             weight_dq = per_tensor_dequantize(weight[start:end, :],
                                               weight_scale[idx])