ci(xpu): push latest tag and use 7-char SHA in nightly image tags (#27299)

.github/workflows/release-docker-intel-xpu-nightly.yml

@@ -23,7 +23,7 @@ jobs:
         id: image_meta
         run: |
           date_tag=$(date +%Y%m%d)
-          commit_hash=$(git rev-parse --short=9 HEAD)
+          commit_hash=$(git rev-parse --short=7 HEAD)
           if [ -z "${commit_hash}" ]; then
             echo "::error::Could not resolve commit hash"
             exit 1
@@ -48,8 +48,10 @@ jobs:
             --build-arg SG_LANG_REPO=https://github.com/sgl-project/sglang.git \
             --build-arg SG_LANG_BRANCH=main \
             --no-cache --progress=plain \
-            -t "intel/sglang-dev:${{ env.IMAGE_TAG }}"
+            -t "intel/sglang-dev:${{ env.IMAGE_TAG }}" \
+            -t "intel/sglang-dev:latest"
 
       - name: Push intel/sglang-dev
         run: |
           docker push "intel/sglang-dev:${{ env.IMAGE_TAG }}"
+          docker push "intel/sglang-dev:latest"