Must someone who performed 'Umrah in Ramadan and forgot to shorten his hair do anything before the Hajj?

Shaving or shortening the hair in 'Umrah is a mandatory ritual according to the majority of scholars, and it is not permissible to exit the state of Ihram before it. Therefore, you must remove sewn garments and avoid the prohibitions of Ihram, then shave or shorten your hair, even if you are in your own country, to complete the 'Umrah and exit Ihram. If you were unaware of the ruling, then what you committed of prohibitions before shaving or shortening does not obligate anything upon you according to Ibn Taymiyyah, except for hunting that is guaranteed by a replacement. And if you entered into Ihram for Hajj before shaving or shortening your hair from 'Umrah, your Ihram for it is not valid and is considered void by the three Imams, and there is nothing upon you for it.