ci: add markfile to pre build

Author: dsx137

.github/workflows/template-publish.yml

@@ -42,3 +42,7 @@ jobs:
         run: |
           PREFIX=ghcr.io/${{ github.repository }}
           KO_DOCKER_REPO=${PREFIX} ko build -B .
+
+      - name: Mark Success
+        run: |
+          touch /tmp/commit-built/.built-success