While resizing the main window or dialogs like the preferences dialog, they disappear at certain sizes:

<img width="746" alt="Screenshot 2023-10-22 at 11 15 45" src="https://github.com/geany/geany-osx/assets/713965/99af9540-3d8d-4a2c-b43a-0a0b7531cc6b">

When the cursor is moved over the dialog or the window is minimized and then re-shown, it starts showing the dialog elements again.

Based on a report from @frlan, this doesn't happen on macOS 13, the window just flickers a bit during the resize.

I've created a bug report upstream here: [6178](https://gitlab.gnome.org/GNOME/gtk/-/issues/6178)