Is repentance and seeking forgiveness for cheating on the baccalaureate exam sufficient, or is retaking the exam required, with the consequent loss of a school year?

You have committed a forbidden act, for the Prophet, peace and blessings be upon him, said: "Whoever cheats us is not of us," and "Whoever cheats is not of me." Seek Allah's forgiveness, resolve not to return to it, and your remorse is proof of the sincerity of your repentance, for he, peace and blessings be upon him, said: "Remorse is repentance." If you can retake the exam, then do so. Otherwise, complete your studies with sincere repentance and uprightness, and avoid cheating in the future. The university degree will then be beneficial.