Fix workflow

.github/workflows/publish.yml

@@ -21,6 +21,8 @@ jobs:
                   github_token: ${{ secrets.GITHUB_TOKEN }}
               env:
                   GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}
+            - name: Checkout code
+              uses: actions/checkout@v2.3.4
             - name: Set up QEMU
               uses: docker/setup-qemu-action@v1.2.0
             - name: Set up Docker Buildx