GH Workflow update for Policy Testing

Overview/Summary

Updating portal testing workflow to only test updated or added policies, instead of all policies everytime.

Please provide any testing evidence to show that your Pull Request works/fixes as described and planned (include screenshots, if appropriate).

[ ] Checked for duplicate Pull Requests
[ ] Associated it with relevant issues, for tracking and closure.
[ ] Ensured my code/branch is up-to-date with the latest changes in the main branch
[ ] Performed testing and provided evidence.
[ ] Ensured contribution guidance is followed.
[ ] Updated relevant and associated documentation.
[ ] Updated the "What's New?" wiki page (located: /docs/wiki/whats-new.md)