Report annotations when being run in GitHub Actions

[macbre]

• https://docs.github.com/en/actions/reference/workflow-commands-for-github-actions#setting-an-error-message
• https://github.com/ansible/ansible-lint/blob/9aee394e02dc856c6218c0e2ab7dfd55c8cd85e4/lib/ansiblelint/formatters/init.py#L102-L139

Example

::warning file=roles/gcloud-env/tasks/main.yml,line=3::[E208] File permissions not mentioned

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Inspired by https://github.com/ansible/ansible-lint#cicd