Fix CUDA 13 wheel installation doc (#32276)

Signed-off-by: Dmitry Tokarev <dtokarev@nvidia.com>

docs/getting_started/installation/gpu.cuda.inc.md

@@ -41,7 +41,8 @@ As of now, vLLM's binaries are compiled with CUDA 12.9 and public PyTorch releas
 # Install vLLM with a specific CUDA version (e.g., 13.0).
 export VLLM_VERSION=$(curl -s https://api.github.com/repos/vllm-project/vllm/releases/latest | jq -r .tag_name | sed 's/^v//')
 export CUDA_VERSION=130 # or other
-uv pip install https://github.com/vllm-project/vllm/releases/download/v${VLLM_VERSION}/vllm-${VLLM_VERSION}+cu${CUDA_VERSION}-cp38-abi3-manylinux_2_31_x86_64.whl --extra-index-url https://download.pytorch.org/whl/cu${CUDA_VERSION}
+export CPU_ARCH=$(uname -m) # x86_64 or aarch64
+uv pip install https://github.com/vllm-project/vllm/releases/download/v${VLLM_VERSION}/vllm-${VLLM_VERSION}+cu${CUDA_VERSION}-cp38-abi3-manylinux_2_35_${CPU_ARCH}.whl --extra-index-url https://download.pytorch.org/whl/cu${CUDA_VERSION}
 ```
 
 #### Install the latest code