crash when deleting courtesy key signature

[sta-ho]

Issue type

Crash or freeze

Bug description

Changing the key at a new line is marked with the key signature at the end of the line above. If you try to remove this signature (e.g. I do not need it for some reasons) by selecting and deleting, the system crashes.

Steps to reproduce

1. Open the MuseScore and create a new score (big +), add any instruments, click OK.
2. Drag a key signature from the left palette and drop it on the beginning of the second line (the first measure at the clef).
3. Click the courtesy key signature at the end of the first line.
4. Press Delete.

Screenshots/Screen recordings

MuseScore Version

MuseScore 4.2 (4.2.0.233521124), Windows 10; MuseScoreNightly-latest-4.2.0-x86_64-portable.exe as of 2023-12-20

Regression

Yes, this is used to work in MU4.1

Operating system

Windows 10

[Jojo-Schmitz]

Came up in https://musescore.org/en/node/358050 and https://musescore.org/en/node/358075 (there slightly different, via a Ctrl+X rather than Del)