crash when deleting courtesy key signature

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.

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

To reproduce:
- open the MuseScore and create a new score (big +), add any instruments, click OK,
- drag a key signature from the left palette and drop it on the beginning of the second line (the first measure at the clef),
- click the key signature at the end of the first line,
- press Delete.