Compatible to PHP 8

As of PHP 8, Name aliases for scalar types (bool, int, float, string) are not supported. Instead, they are treated as class or interface names. For example, using boolean as a type declaration will require the value to be an instanceof the class or interface boolean, rather than of type bool:

See: https://www.php.net/manual/en/language.types.declarations.php#language.types.declarations.base.scalar

We used boolean and we should change it to bool:

https://git.jeyserver.com/yeganemehr/telebot/-/blob/1aa5db4367deb95395a09d86834beb556688a58c/Types/InlineKeyboardButton.php#L224