MSS crashes when clicking "Close other tabs" on main tab

[krasko78]

Issue type

Crash or freeze

Bug description

See steps to reproduce.

Steps to reproduce

MSS 4.4 (latest master)

1. Create a new score (just click Done at the wizard)
2. Click the Parts button and add a couple of parts or more.
3. Click "Open all" while the "Parts" dialog is still open.
4. When all parts open next to the main tab (reading "Untitled score") right-click on it ("Untitled score") and click "Close other tabs" on the context menu.

Actual: MSS crashes.
Expected: MSS closes the other tabs and doesn't crash.

Works fine in 4.3.2.

Screenshots/Screen recordings

No response

MuseScore Version

4.4 (latest master)

Regression

Yes, this used to work in a previous version of MuseScore 4.x

Operating system

Windows 10

Additional context

The NotationSwitchListModel::closeOtherNotations(int index) function iterates over the other tabs and closes them. Along the way the iteration of the first few notations is fine, but then the iteration results in a null notation and currentMasterNotation()->setExcerptIsOpen(notation, false); blows up.