Fix workflow

.github/workflows/publish.yml

@@ -23,6 +23,8 @@ jobs:
                   GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}
             - name: Checkout code
               uses: actions/checkout@v2.3.4
+              with:
+                  ref: main
             - name: Set up QEMU
               uses: docker/setup-qemu-action@v1.2.0
             - name: Set up Docker Buildx