Forgejo connection fails to fork if a fork with an unexpected name already exists

**Describe the bug**

Login doesn't work if I already have a forgejo fork but with a different name than upstream.

**To Reproduce**

1. Fork https://codeberg.org/DI-Day/website/ as `diday-website`
2. Sign in at `https://diday.org/admin/` using Forgejo
3. Click "Fork"
4. See error

**Expected behavior**

It uses my existing fork as intended.

**Screenshots**

**Applicable Versions:**

- Decap CMS version: 3.10.0
- Git provider: Forgejo
- OS: FUCKBOI 26.05 (Yarara)
- Browser version: Firefox 150

- Node.JS version: -

**CMS configuration**

https://codeberg.org/DI-Day/website/src/branch/main/public/admin/config.yml

**Additional context**