feat: [CI] Introduce uv to accelerate pip install (#7127)

### What this PR does / why we need it?
Integrates uv: Significantly accelerates pip install execution and
resolves concurrency issues caused by traditional pip caching
mechanisms.

Why pip install uc-manager is explicitly added:
This project depends on uc-manager. However, installing it via uv pip
install uc-manager currently fails due to a known issue. An issue has
already been filed with the upstream uv repository to address this.
Consequently, we explicitly invoke pip install uc-manager as a temporary
workaround to ensure the build succeeds.
https://github.com/ModelEngine-Group/unified-cache-management/issues/736

Why use UV_SYSTEM_PYTHON: 1:
No virtual environment has been created yet; this configuration has the
same effect as directly using `pip install`.

- vLLM version: v0.16.0
- vLLM main:
15d76f74e2

Signed-off-by: tfhddd <2272751277@qq.com>

.github/workflows/_e2e_nightly_single_node.yaml

@@ -71,11 +71,17 @@ jobs:
     env:
       HF_HUB_OFFLINE: 1
       VLLM_USE_MODELSCOPE: True
+      UV_INDEX_URL: http://cache-service.nginx-pypi-cache.svc.cluster.local/pypi/simple
+      UV_EXTRA_INDEX_URL: https://mirrors.huaweicloud.com/ascend/repos/pypi
+      UV_INDEX_STRATEGY: unsafe-best-match
+      UV_NO_CACHE: 1
+      UV_SYSTEM_PYTHON: 1
     steps:
       - name: Check npu and CANN info
         run: |
           npu-smi info
           cat /usr/local/Ascend/ascend-toolkit/latest/"$(uname -i)"-linux/ascend_toolkit_install.info
+          pip install uv
       
       - name: uninstall vlm vllm-ascend and remove code (if pr test)
         if: ${{ inputs.is_pr_test }}
@@ -110,7 +116,7 @@ jobs:
         if: ${{ inputs.is_pr_test }}
         working-directory: /vllm-workspace/vllm
         run: |
-          VLLM_TARGET_DEVICE=empty pip install -e .
+          VLLM_TARGET_DEVICE=empty uv pip install -e .
       
       - name: Install vllm-project/vllm-ascend
         if: ${{ inputs.is_pr_test }}
@@ -118,8 +124,9 @@ jobs:
         env:
           PIP_EXTRA_INDEX_URL: https://mirrors.huaweicloud.com/ascend/repos/pypi
         run: |
-          pip install -r requirements-dev.txt
-          pip install -v -e .
+          pip install uc-manager
+          uv pip install -r requirements-dev.txt
+          uv pip install -v -e .
 
       - name: Install aisbench
         if: ${{ inputs.is_pr_test }}