Robin Malfait c095071f22
Skip .css files when migrating templates (#17854)
This PR fixes an issue where the upgrade tool also migrates `.css` files
as-if they are content files. This is not the intended behavior.

## Test plan

Ran this on my personal website. 

Before:
<img width="1316" alt="image"
src="https://github.com/user-attachments/assets/2b7337c6-7b88-4811-911f-139ab2e31b3b"
/>

After: 
<img width="1046" alt="image"
src="https://github.com/user-attachments/assets/55f09355-37cb-419b-9924-973cf2681c1d"
/>
2025-05-03 00:48:45 +02:00
..
2024-12-11 15:27:20 +01:00