Because Octokit requires Node 18 or higher now.
See https://github.com/octokit/octokit.js/#fetch-missing .
However, for existing runners, users should manually modify `labels` in the `.runner` file or `runner.labels` in the `config.yaml` file to update. Don't forget to restart.
Reviewed-on: https://gitea.com/gitea/act_runner/pulls/526
Reviewed-by: sillyguodong <sillyguodong@noreply.gitea.com>