Some instruments in the "New Score" dialog contain empty dropdowns in Spanish

### Issue type UI bug (incorrect info or interface appearance) ### Description with steps to reproduce In the "New Score" > "Choose Instruments" dialog, some instruments in Spanish contain empty dropdowns, whereas in other languages they do not contain a dropdown at all (I have only checked English and French). It may be a translation issue of some sort but I haven't identified the root See for example: - Electric Bass / Bajo eléctrico - Contra-alto Flute / Flauta Contralto ### Supporting files, videos and screenshots <img width="1041" height="642" alt="Image" src="https://github.com/user-attachments/assets/4d520457-8ac1-4f8f-941d-b26f363945e4" /> <img width="1035" height="640" alt="Image" src="https://github.com/user-attachments/assets/6b3a6169-9829-4a73-9207-05e0b82632d2" /> ### In which versions of MuseScore Studio is this issue present? 4.7.0 - 5.0 main ### Regression No. ### Operating system macOS 26.5 ### Additional context _No response_ ### Checklist - [x] This report follows the [guidelines](https://github.com/musescore/MuseScore/wiki/Reporting-bugs-and-issues) for reporting bugs and issues - [x] I have verified that this issue has not been logged before, by searching the [issue tracker](https://github.com/musescore/MuseScore/issues) for similar issues - [x] I have attached all requested files and information to this report - [x] I have attempted to identify the root problem as concisely as possible, and have used minimal reproducible examples where possible