[StepSecurity] ci: Harden GitHub Actions

Signed-off-by: StepSecurity Bot <[email protected]>

.github/workflows/stale.yml

@@ -3,13 +3,21 @@ on:
   schedule:
     - cron: "30 1 * * *"
 
+permissions:
+  contents: read
+
 jobs:
   close-issues:
     runs-on: ubuntu-latest
     permissions:
       issues: write
       pull-requests: write
     steps:
+      - name: Harden Runner
+        uses: step-security/harden-runner@a4aa98b93cab29d9b1101a6143fb8bce00e2eac4 # v2.7.1
+        with:
+          egress-policy: audit
+
       - uses: actions/stale@28ca1036281a5e5922ead5184a1bbf96e5fc984e # v9.0.0
         with:
           stale-issue-message: 'This issue has been marked as stale because it has been open for 8 weeks with no activity. Please remove the stale label or comment or this issue will be closed in 1 week.'