Unnecessary key signature added when adding a local key signature on a measure that used to contain a header

Issue type

Engraving bug

Bug description

No response

Steps to reproduce

1. Create a document with more than one instrument.
2. Give it a key signature different from C.
3. Place a line break such that, for example, the last two measures of the first system are pushed to the second system.
4. Select the third measure of the second system (this is the measure which, before inserting the line break, used to contain the header key signature).
5. Add a local key signature to the first staff by ctrl + palette click.
6. See that an unnecessary key signature will also be generated in all the other staves. Furthermore, this unnecessary key signature cannot be deleted.

Screenshots/Screen recordings

https://github.com/musescore/MuseScore/assets/93707756/d8af8965-6066-4ea3-a1e0-06b59d749f86

MuseScore Version

Current master

Regression

No.

Operating system

Windows 11

Additional context

The bug also exists in version 4.0
Fixed in https://github.com/musescore/MuseScore/pull/18279 but the commit in question had to be reverted as it was causing other issues.