What to do with failed BackfillUserDetailsFields?

I recently upgraded to 15.9.1, and just now performed another update to 15.9.8. However, the migration BackfillUserDetailsFields: users is still failing, and I am unsure how to proceed.

For the record, I am fine with losing the data in those fields, but want to ensure GitLab’s stability for future upgrades.

What is my path here? How can I determine if manually marking the migration as completed successfully is the correct thing to do?