Issue #3171366 by bnjmnm: Comments from variables.pcss.css create nonuseful noise in compiled css

core/scripts/css/compile.js

core/themes/claro/css/base/elements.css

core/themes/claro/css/base/off-canvas.theme.css

core/themes/claro/css/components/accordion.css

core/themes/claro/css/components/action-link.css

core/themes/claro/css/components/ajax-progress.module.css

...emes/claro/css/components/autocomplete-loading.module.css

core/themes/claro/css/components/breadcrumb.css

core/themes/claro/css/components/button.css

core/themes/claro/css/components/card.css

core/themes/claro/css/components/content-header.css

core/themes/claro/css/components/details.css

core/themes/claro/css/components/dialog.css

core/themes/claro/css/components/divider.css

core/themes/claro/css/components/dropbutton.css

core/themes/claro/css/components/entity-meta.css

core/themes/claro/css/components/fieldset.css

core/themes/claro/css/components/file.css

.../themes/claro/css/components/form--checkbox-radio--ie.css

core/themes/claro/css/components/form--checkbox-radio.css