Gitea migration behavior is broken

### Gitea Version 1.27，main ### What happened? When canceling a migration and deleting the repository while a migration is in progress, the response returns JSON data instead of redirecting to the correct URL. https://github.com/user-attachments/assets/a50a6fd8-cf6b-418e-8aae-8bc02b293d42 ### How are you running Gitea? _No response_