onnxruntime

Fix the TestCUDAProviderOptions test error (#15649)

The test limits GPU's running memory requirements to 20MB. It might be
enough in the past, but it seems not enough now when we upgrade CUDA to
a newer version or add more kernels/graph transformers to our code.
Therefore we need to increase it. Our test log shows sometimes the model
needs 128MB memory. So I set the limit to 256MB.