[ROCm] Update ROCm Nuget pipeline to ROCm 6.2 (#22461)
1. Update ROCm Nuget pipeline build version to ROCm 6.2
2. Update AMD-GPU Agent Pool base docker image for ROCm Nuget pipeline
test stage. search `AMD GPU pipeline Nuget` page in onenote to see how
to update it.
passed pipeline:
https://aiinfra.visualstudio.com/Lotus/_build/results?buildId=580846&view=results
