[CI]Install clang in dokerfile for triton ascend (#4409)

### What this PR does / why we need it?
Install clang in dokerfile for triton ascend

- vLLM version: v0.13.0
- vLLM main:
d68209402d

Signed-off-by: Meihan-chen <jcccx.cmh@gmail.com>

docs/source/tutorials/DeepSeek-V3.2.md

@@ -31,18 +31,6 @@ If you want to deploy multi-node environment, you need to verify multi-node comm
 
 You can using our official docker image to run `DeepSeek-V3.2` directly..
 
-:::{note}
-We strongly recommend you to install clang make triton ascend stable enough. For Ubuntu, the command is
-
-```bash
-apt-get -y clang-15
-
-update-alternatives --install /usr/bin/clang clang /usr/bin/clang-15 20
-update-alternatives --install /usr/bin/clang++ clang++ /usr/bin/clang++-15 20
-```
-
-:::
-
 :::::{tab-set}
 :sync-group: install
 

docs/source/tutorials/Qwen3-235B-A22B.md

@@ -326,15 +326,7 @@ In this section, we provide simple scripts to re-produce our latest performance.
 - CANN 8.3.RC2
 - torch_npu 2.8.0
 - HDK/driver 25.3.RC1
-- triton_ascend 3.2.0.dev2025110717
-
-**Notice:**
-triton_ascend is required for reproducing best performance of Qwen3-235B in vLLM-Ascend. If it is not installed in your environment, please follow the instructions below:
-
-```bash
-wget https://vllm-ascend.obs.cn-north-4.myhuaweicloud.com/vllm-ascend/triton_ascend-3.2.0.dev2025110717-cp311-cp311-manylinux_2_27_aarch64.whl
-pip install triton_ascend-3.2.0.dev2025110717-cp311-cp311-manylinux_2_27_aarch64.whl
-```
+- triton_ascend 3.2.0
 
 ### Single Node A3 （64G*16）
 

docs/source/tutorials/Qwen3-Next.md

@@ -53,17 +53,6 @@ docker run --rm \
 
 The Qwen3 Next is using [Triton Ascend](https://gitee.com/ascend/triton-ascend) which is currently experimental. In future versions, there may be behavioral changes related to stability, accuracy, and performance improvement.
 
-### Install Clang
-
-We strongly recommend you to install clang make triton ascend stable enough. For Ubuntu, the command is
-
-```bash
-apt-get -y clang-15
-
-update-alternatives --install /usr/bin/clang clang /usr/bin/clang-15 20
-update-alternatives --install /usr/bin/clang++ clang++ /usr/bin/clang++-15 20
-```
-
 ### Inference
 
 :::::{tab-set}