update pytorch examples

[kentwelcome]

Signed-off-by: ericy ericy@infuseai.io

PR checklist

• [x] Ensure you have added or ran the appropriate tests for your PR.
• [x] DCO signed

What type of PR is this? Cherry-pick

What this PR does / why we need it: Update primehub-example

Which issue(s) this PR fixes: ch20357

Special notes for your reviewer:

Does this PR introduce a user-facing change?: