Add additional step to delete all untagged versions

.github/workflows/prune-old-container-images.yml

@@ -10,7 +10,17 @@ jobs:
   prune:
     runs-on: ubuntu-latest
     steps:
-      - uses: actions/delete-package-versions@v5
+      - name: Delete all untagged versions
+        uses: actions/delete-package-versions@v5
+        with:
+          package-name: "${{ github.event.repository.name }}/gitlab"
+          package-type: container
+          # never delete release versions or latest
+          ignore-versions: "^(v.*|latest)$"
+          min-versions-to-keep: 0
+          delete-only-untagged-versions: 'true'
+      - name: Delete all but latest 3 feature branch versions
+        uses: actions/delete-package-versions@v5
         with:
           package-name: "${{ github.event.repository.name }}/gitlab"
           package-type: container