Woocommerce Show Hide Free Shipping based on Shipping Class

add_filter( 'woocommerce_package_rates', 'c2code_hide_free_shipping_for_shipping_class', 9999, 2 );
function c2code_hide_free_shipping_for_shipping_class( $rates, $package ) {
   $shipping_class_target = 61; // shipping class ID 
   $in_cart = false;
   foreach ( WC()->cart->get_cart_contents() as $key => $values ) {
      if ( $values[ 'data' ]->get_shipping_class_id() == $shipping_class_target ) {
         $in_cart = true;
         break;
      } 
   }
   if ( $in_cart ) {
      unset( $rates['free_shipping:4'] ); // shipping method ID 
   }
   return $rates;
}