why is this workflow failing...

.github/workflows/docker-image.yml

@@ -1,13 +1,24 @@
 name: Binder Image
 on:
-  workflow_dispatch: null
-  push: null
+  workflow_dispatch:
+  push:
+
 jobs:
   build:
     runs-on: ubuntu-latest
     permissions: write-all
     steps:
       - uses: actions/checkout@v3
+
+      - name: Pre-pull base image (retry)
+        run: |
+          for i in 1 2 3 4 5; do
+            docker pull python:3.12-slim && exit 0
+            echo "Docker Hub pull failed (attempt $i). Retrying in 15s..."
+            sleep 15
+          done
+          exit 1
+
       - name: Publish to GitHub Container Registry
         uses: elgohr/Publish-Docker-Github-Action@v5
         with:
@@ -15,4 +26,3 @@ jobs:
           username: ${{ github.actor }}
           password: ${{ secrets.GITHUB_TOKEN }}
           registry: ghcr.io
-