Fix ImportError in build.py (#6231)
Fix ImportError in build.py (#6231)

There is a possible ImportError where build.py can import the wrong 'util' package if there are others present in `sys.path` already
microsoft/onnxruntime,microsoft/onnxruntime,microsoft/onnxruntime,microsoft/onnxruntime,microsoft/onnxruntime,microsoft/onnxruntime,microsoft/onnxruntime,microsoft/onnxruntime,microsoft/onnxruntime,microsoft/onnxruntime,microsoft/onnxruntime,microsoft/onnxruntime