fix(wren-ai-service): fetch the branch in checkout action (#639)

.github/workflows/ai-service-release-stable-image.yaml

@@ -78,6 +78,8 @@ jobs:
     runs-on: ubuntu-latest
     steps:
       - uses: actions/checkout@v4
+        with:
+          ref: ${{ github.ref }}
       - name: Set up QEMU
         uses: docker/setup-qemu-action@v3
       - name: Set up Docker Buildx
@@ -103,4 +105,4 @@ jobs:
           platforms: linux/amd64,linux/arm64
           tags: ${{ steps.meta.outputs.tags }}
           context: ./wren-ai-service
-          file: ./wren-ai-service/docker/Dockerfile
+          file: ./wren-ai-service/docker/Dockerfile