Dimension generator preview does not work after 1.21.5 when using presets

If you go to the [Dimension Generator](https://misode.github.io/dimension/), using the presets `minecraft:overworld` and `minecraft:nether`, the biome layouts do not appear in the preview after version 1.21.5.

<img width="1920" height="919" alt="Image" src="https://github.com/user-attachments/assets/4647d0a0-c102-46e5-b8eb-a8fa3ef65398" />