onnxruntime

Fix Multi GPU TensorRT tests (#17269)

### Description
* Integrate `trt_multi_gpu` test stage in ORT post merge CI (Win-2xA10
vm)
* Deprecate Linux MultiGPU TRT CI (This vm will be deprecated soon)
* Add multi gpu support to existing C# test cases
* Deprecate unfunctional flag `--enable_multi_device_tests`

### Motivation and Context
* Two contexts of replacing Linux MultiGPU TRT CI:
* Flag `--enable_multi_device_tests` is not functional, which cannot
detect issues like #17036
* The Linux-2xM60 VM of this CI pool is about to be deprecated 9/6/23.
Need to enable this test in other dualGPU vm pool.