You can use “woocommerce_get_price_html” filter to remove class from span tag like:
add_filter( 'woocommerce_get_price_html', 'remove_class_price_html', 10, 2 );
function remove_class_price_html( $price, $product ) {
return str_replace( 'woocommerce-Price-currencySymbol', '', $price );
}
Or else you can use preg_replace to remove class from both span tags.