Update token

Author: holtskinner

.github/workflows/update-a2a-types.yml

@@ -64,7 +64,7 @@ jobs:
       - name: Create Pull Request if generated file changed
         uses: peter-evans/create-pull-request@v6
         with:
-          token: ${{ secrets.GITHUB_TOKEN }}
+          token: ${{ secrets.A2A_BOT_PAT }}
           committer: a2a-bot <[email protected]>
           author: a2a-bot <[email protected]>
           commit-message: "chore: 🤖 Auto-update A2A schema from specification"