Removed unused filter for opacity, fix #6408

apps/files/css/detailsView.scss

apps/files/css/files.scss

apps/files/css/mobile.scss

apps/files_sharing/css/public.scss

apps/files_versions/css/versions.css

core/css/apps.scss

core/css/guest.css

core/css/header.scss

core/css/styles.scss

core/css/tooltip.scss

core/search/css/results.css

settings/css/settings.scss