[CUDA12] set_device change (#94864)
This PR adds workaround for CUDA 12 [`cudaSetDevice` change](https://docs.nvidia.com/cuda/cuda-runtime-api/group__CUDART__DEVICE.html#group__CUDART__DEVICE_1g159587909ffa0791bbe4b40187a4c6bb) which will always create primary context on target device. So operations like this:
```Python
import torch
x = torch.randn(1, device="cuda:1")
```
would always create primary context on on device `cuda:1` because it is creating a tensor on it and on device `cuda:0` because the destructor of CUDA Device guard calls `cudaSetDevice(0)`.
After this PR the CUDA Device guard will not call `cudaSetDevice(0)` if primary context does not exist on `cuda:0`.
Pull Request resolved: https://github.com/pytorch/pytorch/pull/94864
Approved by: https://github.com/malfet, https://github.com/atalman, https://github.com/ezyang
