QML `StyledMenuLoader`: Created graphical object was not placed in the graphics scene

Issue type

UX/Interaction bug (incorrect behaviour)

Description with steps to reproduce

To Reproduce

1. Launch MuseScore 4.
2. Interact with any menu bar item or contextual dropdown driven by StyledMenuLoader.qml.
3. Observe that the menu overlay fails to appear visually.
4. Check terminal output for QML runtime errors.

Expected behavior

StyledMenuLoader.qml should dynamically instantiate menu popups attached to the active window scene graph overlay regardless of the parent item's visual parentage status.

Supporting files, videos and screenshots

Describe the bug

When attempting to open UI menus managed by StyledMenuLoader.qml under certain window manager configurations or non-standard display contexts, the menu fails to render visually. The system logs a critical Qt Quick runtime error indicating that the dynamic menu component was instantiated without being placed inside a valid graphics scene, followed by cascading binding loop errors in PopupContent.qml.

Log Output

ERROR | GuiApp::perform | error: qrc:/qml/Muse/UiComponents/StyledMenuLoader.qml:28:1: QML StyledMenuLoader: Created graphical object was not placed in the graphics scene.
qrc:/qml/Muse/UiComponents/PopupContent.qml:45:5: QML PopupContent: Binding loop detected for property "implicitWidth

### In which versions of MuseScore Studio is this issue present?

4.4.3

### Regression

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

### Operating system

 - host os: `Linux 6.6.68, NixOS, 24.05 (Uakari), 24.05.20241230.b134951`  - version: `nix-env (Nix) 2.18.8`

### Additional context

_No response_

### Checklist

- [x] This report follows the [guidelines](https://github.com/musescore/MuseScore/wiki/Reporting-bugs-and-issues) for reporting bugs and issues
- [x] I have verified that this issue has not been logged before, by searching the [issue tracker](https://github.com/musescore/MuseScore/issues) for similar issues
- [x] I have attached all requested files and information to this report
- [x] I have attempted to identify the root problem as concisely as possible, and have used minimal reproducible examples where possible

Start with qrc:/qml/Muse/UiComponents/StyledMenuLoader.qml at line 28 and reproduce the menu interaction in MuseScore 4.4.3. Inspect the related binding-loop report at qrc:/qml/Muse/UiComponents/PopupContent.qml:45. Done means menu popups appear in the active window scene and the reported QML runtime errors no longer occur.