Error return value of `http.ListenAndServe` is not checked (errcheck)

issues found

The following actions uses node12 which is deprecated and will be forced to run on node16: actions/checkout@v2, golangci/golangci-lint-action@v2. For more info: https://github.blog/changelog/2023-06-13-github-actions-all-actions-will-run-on-node16-instead-of-node12-by-default/

The `save-state` command is deprecated and will be disabled soon. Please upgrade to using Environment Files. For more information see: https://github.blog/changelog/2022-10-11-github-actions-deprecating-save-state-and-set-output-commands/