onnx_graphsurgeon: fix Sequence Tensor bug

[inisis]

Hi, when using graphsurgeon to handle model with SequenceConstruct operator, constant folding will raise an error, this pr helps fix it, model is provided model.zip.

current output after constant folding looks like this:

expected output should look like this:

[inisis]

@pranavm-nvidia please review

[inisis]

@rajeevsrao Hi, can this be merged.

[inisis]

@pranavm-nvidia @rajeevsrao Hi, is there any update? This pr really helps.