Remove the checkout logic to avoid injection (#24442)

Author: wyunchi-ms

.github/workflows/pr-labeled.yml

@@ -14,10 +14,6 @@ jobs:
       pull-requests: write
       contents: read
     steps:
-    - uses: actions/checkout@v3
-      with:
-        sparse-checkout: |
-          .github
     - name: process label
       shell: pwsh
       run: .github/workflows/script/PrLabeled.ps1 -LabelName "${{ github.event.label.name }}" -PrUrl $env:PR