fix(security-scan): set continue-on-error on Dependency Review step

Dependency Review requires GitHub Dependency Graph, which is not available
for iOS/SPM repos where packages are embedded in .xcodeproj. Marking as
non-blocking so CI does not fail on unsupported repo types.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

.github/workflows/repo-pipeline.yml

@@ -173,6 +173,7 @@ jobs:
 
       - name: Dependency Review
         if: ${{ github.event_name == 'pull_request' }}
+        continue-on-error: true
         uses: actions/dependency-review-action@v4
 
   ai-review: