Fix community call workflow: use PROJECT_READ_TOKEN for project board access

The default GITHUB_TOKEN cannot access org-level ProjectV2 nodes via
GraphQL, causing the agenda collection step to fail.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

Author: GiggleLiu

.github/workflows/community-call.yml

@@ -13,7 +13,7 @@ jobs:
       - name: Collect agenda from project board
         id: agenda
         env:
-          GH_TOKEN: ${{ secrets.GITHUB_TOKEN }}
+          GH_TOKEN: ${{ secrets.PROJECT_READ_TOKEN }}
         run: |
           # Fetch issues in "Review pool", "Final review", and "Ready" columns
           QUERY='query {