fix: try using just 'pythoncodespace' for the package name in cleanup.yml

Author: ryboe

.github/workflows/cleanup.yml

@@ -14,7 +14,7 @@ jobs:
       - name: Delete untagged images
         uses: actions/delete-package-versions@v5
         with:
-          package-name: ${{ github.repository }}
+          package-name: pythoncodespace
           package-type: container
           delete-only-untagged-versions: "true"
           min-versions-to-keep: 0