Man pages matching name borg-key-migrate-to-repokey in section 1:

borg-key-migrate-to-repokey.1.en	debian 10 / borgbackup
borg-key-migrate-to-repokey.1.en	debian 11 / borgbackup
borg-key-migrate-to-repokey.1.en	debian 12 / borgbackup