Add mobile CIs to list run by script for external PRs. (#18094)
### Description
<!-- Describe your changes. -->
Add the mobile CIs to the list so we check external PRs don't break
those.
### Motivation and Context
<!-- - Why is this change required? What problem does it solve?
- If it fixes an open issue, please link to the issue here. -->
Recent external PR was found to break iOS CI after checkin