Disable Google Open Sans font in the Admin area

gistfile1.phtml

/**
 * Disable Google Open Sans font in the Admin area . Implementation idea from ... https://wordpress.org/plugins/disable-google-fonts/
 */
function myplugin_admin_area_minus_open_sans_style() {
        // Remove Open Sans. Doesn't work :-( 
        // See 'Disable_Google_Fonts' class below as an alternative.
        wp_dequeue_style('open-sans-css'); 
        
        // Add custom style definitions to compensate for the removal of Open Sans
        wp_enqueue_style('myplugin-admin-minus-open-sans', plugins_url( 'css/admin-minus-open-sans.css', __FILE__ ), false, '1.0.0', 'all');
}
add_action('admin_enqueue_scripts', 'myplugin_admin_area_minus_open_sans_style', 9999);

class Disable_Google_Fonts {
        public function __construct() {
	      add_filter( 'gettext_with_context', array( $this, 'disable_open_sans' ), 888, 4 );
        }

        public function disable_open_sans($translations, $text, $context, $domain) {
	      if ( 'Open Sans font: on or off' == $context && 'on' == $text ) {
		    $translations = 'off';
	      }
	      return $translations;
        }
}

if ( is_admin() ) { 
        $disable_google_fonts = new Disable_Google_Fonts; 
}