(build) Allows External Forks to Target Builds

[JPRuskin]

Description Of Changes

Allows forks to trigger the build using repository secrets.

Does not trigger a build if the workflows are changed. If the workflows are changed, a maintainer will have to manually trigger a build.

Motivation and Context

Folk may submit changes from forks.

Testing

Operating Systems Testing

Change Types Made

• ~[ ] Bug fix (non-breaking change).~
• [x] Feature / Enhancement (non-breaking change).
• ~[ ] Breaking change (fix or feature that could cause existing functionality to change).~
• ~[ ] Documentation changes.~
• ~[ ] PowerShell code changes.~

Change Checklist

• ~[ ] Requires a change to the documentation.~
• ~[ ] Documentation has been updated.~
• ~[ ] Tests to cover my changes, have been added.~
• ~[ ] All new and existing tests passed?~
• ~[ ] PowerShell code changes: PowerShell v3 compatibility checked?~