Removing soloed instrument leaves other instruments muted

Issue type

UX/Interaction bug (incorrect behaviour)

Description with steps to reproduce

1. Open score with more than one instrument (see attached score below)
2. Solo one instrument
3. Remove that instrument

Actual behaviour: All other instruments remain muted
Expected behaviour: Other instruments should be unmuted

Supporting files, videos and screenshots

SoloInstrumentBug.zip

https://github.com/user-attachments/assets/56d1f3b5-f049-4815-ad82-f2bbb0a732b4

What is the latest version of MuseScore Studio where this issue is present?

4.5.2 and nightly:
OS: Windows 10 Version 22H2 or later, Arch.: x86_64, MuseScore Studio version (64-bit): 4.6.0-251950329, revision: github-musescore-musescore-1def3c6

Regression

I was unable to check

Operating system

Windows 10

Additional context

No response

Checklist

• This report follows the guidelines for reporting bugs and issues
• I have verified that this issue has not been logged before, by searching the issue tracker for similar issues
• I have attached all requested files and information to this report
• I have attempted to identify the root problem as concisely as possible, and have used minimal reproducible examples where possible

Start by reproducing the issue with the attached SoloInstrumentBug.zip in MuseScore Studio: solo one instrument, then remove it and observe the remaining instruments. Trace the solo and instrument-removal interaction until the mute state is updated; done means removing the soloed instrument leaves all other instruments audible, with coverage for the reported steps.