Update GitHub Actions workflows. (#751)

This PR was automatically generated by the
update-workflows-ecosystem-providers workflow in the pulumi/ci-mgmt
repo, from commit a94a4e21904c11dcb4a6d42bed9806407ac2cdad.

Author: pulumi-bot

.github/workflows/comment-on-stale-issues.yml

@@ -38,3 +38,5 @@ jobs:
 
         repo-token: ${{ secrets.GITHUB_TOKEN }}
         loglevel: DEBUG
+        # Set dry-run to true to not perform label or close actions.
+        dry-run: true