Fix Linux MultiGPU TensorRT CI (#15697)
### Description
* Reverting default TensorRT version to 8.5 as temporary fix
* Apart from that, this PR temporarily leaves this CI as a place to
validate user behavior that uses TRT 8.5 with latest ORT
### Context
* This CI pool equips 2xTesla M60 GPUs, which are no longer supported by
TensorRT 8.6.
* Currently, other CIs are using single-T4 VM but there's no VM with
2xT4 or other suitable dualGPU in the range.
* Once we decide which VM instance for this CI to migrate to, TRT8.6 can
be enabled on this CI
* According to
[Nvidia](https://docs.nvidia.com/deeplearning/tensorrt/release-notes/index.html):
* TensorRT 8.5.3 was the last release supporting NVIDIA Kepler (SM 3.x)
and NVIDIA Maxwell (SM 5.x) devices. *These devices are no longer
supported in TensorRT 8.6*. NVIDIA Pascal (SM 6.x) devices are
deprecated in TensorRT 8.6.
