[Doc][CPU] Fix index link for CPU regular release wheels (#31015)

Signed-off-by: jiang1.li <jiang1.li@intel.com>

docs/getting_started/installation/cpu.arm.inc.md

@@ -19,12 +19,12 @@ Pre-built vLLM wheels for Arm are available since version 0.11.2. These wheels c
 
 ```bash
 export VLLM_VERSION=$(curl -s https://api.github.com/repos/vllm-project/vllm/releases/latest | jq -r .tag_name | sed 's/^v//')
-uv pip install vllm --extra-index-url https://wheels.vllm.ai/${VLLM_VERSION}/cpu --index-strategy first-index
+uv pip install https://github.com/vllm-project/vllm/releases/download/v${VLLM_VERSION}/vllm-${VLLM_VERSION}+cpu-cp38-abi3-manylinux_2_35_aarch64.whl
 ```
 
 ??? console "pip"
     ```bash
-    pip install vllm==${VLLM_VERSION}+cpu --extra-index-url https://wheels.vllm.ai/${VLLM_VERSION}/cpu
+    pip install https://github.com/vllm-project/vllm/releases/download/v${VLLM_VERSION}/vllm-${VLLM_VERSION}+cpu-cp38-abi3-manylinux_2_35_aarch64.whl
     ```
 
 !!! warning "set `LD_PRELOAD`"

docs/getting_started/installation/cpu.x86.inc.md

@@ -23,12 +23,12 @@ Pre-built vLLM wheels for x86 with AVX512 are available since version 0.13.0. To
 export VLLM_VERSION=$(curl -s https://api.github.com/repos/vllm-project/vllm/releases/latest | jq -r .tag_name | sed 's/^v//')
 
 # use uv
-uv pip install vllm --extra-index-url https://wheels.vllm.ai/${VLLM_VERSION}/cpu --index-strategy first-index --torch-backend cpu
+uv pip install https://github.com/vllm-project/vllm/releases/download/v${VLLM_VERSION}/vllm-${VLLM_VERSION}+cpu-cp38-abi3-manylinux_2_35_x86_64.whl --torch-backend cpu
 ```
 ??? console "pip"
     ```bash
     # use pip
-    pip install vllm==${VLLM_VERSION}+cpu --extra-index-url https://wheels.vllm.ai/${VLLM_VERSION}/cpu --extra-index-url https://download.pytorch.org/whl/cpu
+    pip install https://github.com/vllm-project/vllm/releases/download/v${VLLM_VERSION}/vllm-${VLLM_VERSION}+cpu-cp38-abi3-manylinux_2_35_x86_64.whl --extra-index-url https://download.pytorch.org/whl/cpu
     ```
 !!! warning "set `LD_PRELOAD`"
     Before use vLLM CPU installed via wheels, make sure TCMalloc and Intel OpenMP are installed and added to `LD_PRELOAD`: