fix(ci): remove invalid secrets check in workflow conditional

GitHub Actions does not allow direct access to secret values in if conditions for security reasons. Removed the invalid 'secrets.UNITY_EMAIL != ""' check while keeping the repository check that properly skips Unity tests for PRs from forks.

Co-Authored-By: Claude <noreply@anthropic.com>

Author: JasonXuDeveloper

.github/workflows/ci.yml

@@ -85,7 +85,7 @@ jobs:
 
       - name: Run Unity tests
         # Skip Unity tests for external PRs (secrets not available in forks)
-        if: github.event.pull_request.head.repo.full_name == github.repository || secrets.UNITY_EMAIL != ''
+        if: github.event.pull_request.head.repo.full_name == github.repository
         uses: game-ci/unity-test-runner@v4
         id: unity-tests
         env: