Skip Vally eval job for fork-originated pull requests

[Copilot]

The "Vally evaluations / eval-job" workflow was failing for pull requests opened from forked repositories, reporting 45/45 eval failures.

Root cause

GitHub Actions never exposes repository secrets (COPILOT_GITHUB_TOKEN) to workflow runs triggered by pull_request events from a fork. Without the token, vally's copilot-sdk executor can't create a session:

Error: Execution failed: Error: Session was not created with authentication info or custom provider

This was confirmed by comparing against other recent runs of the same workflow: same-repo PR runs either passed or failed on legitimate grader mismatches, while every fork-originated run failed uniformly on this session error regardless of the code changes in the PR.

Fix

• .github/workflows/vally-eval.yml: added a job-level if condition that skips eval-job when the run is a pull_request from a fork (head.repo.full_name != github.repository), while still running normally for same-repo PRs and manual workflow_dispatch runs.

This avoids surfacing a false failure for a structural GitHub Actions limitation, without exposing secrets to untrusted fork-submitted code.

[azure-pipelines]

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