Use 'gh' command to download artifacts

.github/workflows/post-pr-comment.yml

@@ -13,11 +13,9 @@ jobs:
     runs-on: ubuntu-latest
     steps:
       - name: Download artifact
-        uses: dawidd6/action-download-artifact@af92a8455a59214b7b932932f2662fdefbd78126
-        with:
-          workflow: ${{ github.event.workflow_run.workflow_id }}
-          workflow_conclusion: success
-          name: comment
+        run: gh run download "${{ github.event.workflow_run.id }}" --repo "${{ github.repository }}" --name "comment"
+        env:
+          GITHUB_TOKEN: ${{ github.token }}
       - run: |
           PR=$(grep -o '^[0-9]\+$' pr.txt)
           PR_HEAD_SHA=$(gh api "/repos/${{ github.repository }}/pulls/${PR}" --jq .head.sha)