Is there a Hadith from the Prophet, may God’s prayers and peace be upon him, indicating that Satan regrets leading a servant into disobedience due to the servant's frequent seeking of forgiveness?

Indeed, there is much encouragement in the Quran and Sunnah for abundant seeking of forgiveness (istighfar) and repentance to Allah Almighty, along with clarification of their merits. The hadith you are referring to might be the one narrated by Abu Nu'aym in Hilyat al-Awliya' from 'Ikrimah: "Verily, Satan beautifies the sin for the servant until he commits it. Then, when he commits it, Satan disavows himself of him. And the servant continues to weep over it, supplicate to his Lord, and humble himself until that sin and what preceded it are forgiven for him. Then Satan regrets that sin when he made him commit it, for the sin and what preceded it were forgiven for him." We have not found any authentication for this report.