This script removes unused translations from the `en.json` source translation file:
- Parse `en.json` to build a list of all keys, e.g. `controlnet.depthAnything`
- Check every frontend file for every key
- If the key is not found, it is removed from the translation file
- Exact matches (e.g. `controlnet.depthAnything`) and stem matches (e.g. `depthAnything`) are ignored
