fix: checkout the code (#236)

Author: jamesdangercarpenter

.github/workflows/publish_container.yml

@@ -8,6 +8,9 @@ jobs:
   publish:
     runs-on: ubuntu-latest
     steps:
+      - name: Checkout code
+        uses: actions/checkout@v4
+
       - name: Login to Docker Hub
         uses: docker/login-action@v3
         with: