[CI] Set token permissions for reminder comment CI job (vllm-project#17728)

Co-authored-by: Copilot Autofix powered by AI <62310815+github-advanced-security[bot]@users.noreply.github.com>
Signed-off-by: Yuqi Zhang <[email protected]>

Author: 2 people

.github/workflows/reminder_comment.yml

@@ -1,4 +1,6 @@
 name: PR Reminder Comment Bot
+permissions:
+  issues: write
 on:
   pull_request_target:
     types: [opened]