onnxruntime

Fix bug with saving model optimized by inference session (#16716)

### Description
A [previous PR](https://github.com/microsoft/onnxruntime/pull/16531)
added a temporary directory to save the model optimizations after
loading a model into an `InferenceSession`. Many models that have an
external data file, however, require the data file to be in the same
directory as the ONNX model file. Because the model is saved in a
temporary directory and the data is saved in another directory, this
causes a `FileNotFoundError` error when trying to load the model in the
temporary directory.

This PR fixes this error by saving the external data file in the same
directory that the optimized model is located in.

### Motivation and Context
This PR fixes a bug with using a temporary directory while running the
optimizer for models that have an external data file.