publish torchrun example via Dockerfile (kubeflow#2018)

Signed-off-by: PeterWrighten <peterwrighten@gmail.com>

.github/workflows/publish-example-images.yaml

@@ -38,6 +38,8 @@ jobs:
             dockerfile: examples/pytorch/elastic/imagenet/Dockerfile
           - component-name: pytorch-elastic-example-echo
             dockerfile: examples/pytorch/elastic/echo/Dockerfile
+          - component-name: pytorch-cpu-demo-torchrun-cpu
+            dockerfile: examples/pytorch/cpu-demo/Dockerfile
           - component-name: xgboost-dist-iris
             dockerfile: examples/xgboost/xgboost-dist/Dockerfile
             context: examples/xgboost/xgboost-dist