GTK4: Cannot click font family suggestions
#### Summary:
<!-- Summarize the issue/suggestion concisely: -->
If the list of font family names matching what you type in the toolbar appears while the mouse is where that list would be, you cannot interact with it using the mouse until you move the mouse away.
#### Steps to reproduce:
<!-- Describe what you did (step-by-step) so we can reproduce: -->
- Switch to the text tool
- Click on the font family name
- Move the mouse just below that widget
- Backspace the name
- Type a letter so suggestions appear below the mouse (e.g. T)
- Try to highlight or click on a suggestion (e.g. Times New Roman) or scroll
#### What happened?
You will click on or scroll whatever's behind the suggestion list.
#### What should have happened?
The suggestion list reacts to the mouse and can be clicked.
#### Sample attachments:
<details><summary>Version info</summary>
```
Inkscape 1.5-dev (2c9c14a314, 2025-06-09, custom)
Compile (Run)
GLib version: 2.84.2
GTK version: 4.18.5 (4.18.5)
glibmm version: 2.84.0
gtkmm version: 4.18.0
libxml2 version: 2.12.10
libxslt version: 1.1.43
Cairo version: 1.18.4 (1.18.4)
Pango version: 1.56.3 (1.56.3)
HarfBuzz version: 11.2.1 (11.2.1)
Poppler version: 25.05.0
OS version: Windows 11 24H2
```
</details>
issue