ci: 将 workflow 的 runs-on 改为 internal_docker

自托管 Gitea runner 只注册了 internal_docker 标签，ubuntu-latest 会导致 job 永远排队。

Co-authored-by: Cursor <cursoragent@cursor.com>

.github/workflows/track-upstream.yml

@@ -36,7 +36,7 @@ permissions:
 jobs:
   track:
     name: Check upstream & auto-bump
-    runs-on: ubuntu-latest
+    runs-on: internal_docker
     steps:
       - uses: actions/checkout@v4
         with: