[ci] add nginx cache config for Ascend NPU CI environment (#10323)

.github/workflows/tests_npu.yml

@@ -49,6 +49,12 @@ jobs:
       - name: Checkout
         uses: actions/checkout@v6
 
+      - name: Set nginx-cache for Ascend CI
+        run: |
+          sed -Ei 's@(ports|archive).ubuntu.com@cache-service.nginx-pypi-cache.svc.cluster.local:8081@g' /etc/apt/sources.list
+          pip config set global.index-url http://cache-service.nginx-pypi-cache.svc.cluster.local/pypi/simple
+          pip config set global.trusted-host cache-service.nginx-pypi-cache.svc.cluster.local
+
       - name: Install uv
         uses: astral-sh/setup-uv@v7
         with: