[CI] Add daily images build for nightly ci (#3989)

### What this PR does / why we need it?
Given the current excessively long build time of our nightly-ci, I
recommend installing necessary, confirmed versions of packages in the
Docker image to reduce the time required for integration testing.
Including Mooncake vllm with fixed tags, This is expected to reduce
nightly-ci duration by 2 hours.

- vLLM version: v0.11.0
- vLLM main:
2918c1b49c

---------

Signed-off-by: wangli <wangli858794774@gmail.com>

.github/workflows/_nightly_image_build.yaml

@@ -0,0 +1,74 @@
+name: 'image / nightly / Ubuntu / test'
+
+on:
+  schedule:
+    - cron: '0 0,4,8,12,14 * * *'
+  workflow_call:
+    inputs:
+      target:
+        required: true
+        type: string
+        description: 'Target architecture, e.g., a2, a3'
+    outputs:
+      image-tag:
+        description: 'The built image tag'
+        value: ${{ jobs.build-and-sync.outputs.image-tag }}
+    secrets:
+      HW_USERNAME:
+        required: true
+      HW_TOKEN:
+        required: true
+
+# This workflow builds and pushes Docker images for nightly-ci
+# It will be built base on the quay.io/ascend/vllm-ascend:main
+# And have some customizations for nightly testing, pushing to Huawei Cloud SWR
+jobs:
+  build-and-sync:
+    runs-on: ubuntu-22.04-arm
+
+    strategy:
+      matrix:
+        target: ${{ fromJson(github.event_name == 'schedule' && '["a2","a3"]' || format('["{0}"]', inputs.target || 'a3')) }}
+
+    outputs:
+      image-tag: ${{ steps.build-image.outputs.image-tag }}
+
+    steps:
+      - uses: actions/checkout@v4
+
+      - name: Show build target
+        run: |
+          echo "Building target: ${{ matrix.target }}"
+
+      - name: Login to Huawei Cloud SWR
+        id: login-swr
+        if: ${{ env.HW_USERNAME != '' && env.HW_TOKEN != '' }}
+        run: |
+          echo "${{ env.HW_TOKEN }}" | docker login -u "${{ env.HW_USERNAME }}" --password-stdin swr.cn-southwest-2.myhuaweicloud.com
+        env:
+          HW_USERNAME: ${{ secrets.HW_USERNAME }}
+          HW_TOKEN: ${{ secrets.HW_TOKEN }}
+
+      - name: Build image
+        id: build-image
+        run: |
+          TARGET="${{ matrix.target }}"
+          IMAGE_TAG="swr.cn-southwest-2.myhuaweicloud.com/base_image/ascend-ci/vllm-ascend:nightly-${TARGET}"
+
+          echo "Building image: $IMAGE_TAG"
+          docker build \
+            --network host \
+            --platform linux/arm64 \
+            -f .github/Dockerfile.nightly.${TARGET} \
+            --build-arg CANN_VERSION="8.3.rc1" \
+            --build-arg UBUNTU_VERSION="22.04" \
+            --build-arg PYTHON_VERSION="3.11" \
+            -t "$IMAGE_TAG" .
+
+          echo "image-tag=$IMAGE_TAG" >> $GITHUB_OUTPUT
+
+      # To avoid pushing images from forks, only push when the repository owner is 'vllm-project'
+      - name: Push image to SWR
+        if: ${{ github.repository_owner == 'vllm-project' && steps.login-swr.conclusion == 'success' }}
+        run: |
+          docker push ${{ steps.build-image.outputs.image-tag }}