newsupernova/vendor/magento/magento2-base/dev/tools/grunt/configs/cssmin.json

{
    "options": {
        "report": "gzip",
        "keepSpecialComments": 0
    },
    "setup": {
        "files": {
            "<%= path.css.setup %>/setup.css": "<%= path.css.setup %>/setup.css"
        }
    },
    "updater": {
        "files": {
            "<%= path.css.updater %>/updater.css": "<%= path.css.updater %>/updater.css"
        }
    }
}