Update CUDA build configs

[snnn]

Description:

1. Fix Nuget package build break caused by Remove docs that have been migrated to https://onnxruntime.ai/docs #6225
2. Delete Dockerfile.centos_gpu. It is not used anywhere.
3. Fix Linux CUDA 10.2 build error caused by glibc upgrade

Motivation and Context

• Why is this change required? What problem does it solve?
• If it fixes an open issue, please link to the issue here.

[jywu-msft]

I'm worried about removing cudnn_home option.
on some platforms (e.g. Nvidia JetPack), they are pre-installed locations and cuda_home/cudnn_home are not the same.
the user would have to move cudnn libraries to cuda location (which may not be possible for all cases)

[jywu-msft]

i'm worried about removing cudnn_home build option and how it could break some user's scenarios.

[snnn]

I'm worried about removing cudnn_home option.
on some platforms (e.g. Nvidia JetPack), they are pre-installed locations and cuda_home/cudnn_home are not the same.
the user would have to move cudnn libraries to cuda location (which may not be possible for all cases)

i'm worried about removing cudnn_home build option and how it could break some user's scenarios.

Reverted.

updated.