[CI] Prevents triggering inactive issue/pr check for fork

Author: wzshiming

.github/workflows/stale.yml

@@ -7,6 +7,8 @@ on:
 
 jobs:
  close-issues-and-pull-requests:
+ # Prevents triggering on forks or other repos
+ if: github.repository == 'vllm-project/vllm'
  permissions:
  issues: write
  pull-requests: write