### Godot version

v4.0.beta.custom_build [eaf306e0b]

### System information

Windows 10

### Issue description

Selecting a `Window` node in the Editor's SceneTree results in the message
```
editor/editor_data.cpp:1058 - Parameter "p_node" is null.
```
and the Inspector shows empty content instead of the Window's properties.

I would expect, that clicking on a node in the SceneTree lets me edit the properties of the node.

Bisecting shows that this behavior got introduced in #71770

### Steps to reproduce

1. Create a Window node
2. Click on the Window node in the Editor's SceneTree

### Minimal reproduction project

N/A
deselect_all_colors_button->set_icon(get_theme_icon(SNAME("ThemeDeselectAll"), SNAME("EditorIcons")));
			select_all_colors_button->set_icon(get_theme_icon(SNAME("ThemeSelectAll"), SNAME("EditorIcons")));
			select_full_colors_button->set_icon(get_theme_icon(SNAME("ThemeSelectFull"), SNAME("EditorIcons")));
			select_constants_icon->set_texture(get_theme_icon(SNAME("MemberConstant"), SNAME("EditorIcons")));
			deselect_all_constants_button->set_icon(get_theme_icon(SNAME("ThemeDeselectAll"), SNAME("EditorIcons")));
			select_all_constants_button->set_icon(get_theme_icon(SNAME("ThemeSelectAll"), SNAME("EditorIcons")));
			select_full_constants_button->set_icon(get_theme_icon(SNAME("ThemeSelectFull"), SNAME("EditorIcons")));
			select_fonts_icon->set_texture(get_theme_icon(SNAME("Font"), SNAME("EditorIcons")));
			deselect_all_fonts_button->set_icon(get_theme_icon(SNAME("ThemeDeselectAll"), SNAME("EditorIcons")));
			select_all_fonts_button->set_icon(get_theme_icon(SNAME("ThemeSelectAll"), SNAME("EditorIcons")));
			select_full_fonts_button->set_icon(get_theme_icon(SNAME("ThemeSelectFull"), SNAME("EditorIcons")));
			select_font_sizes_icon->set_texture(get_theme_icon(SNAME("FontSize"), SNAME("EditorIcons")));
			deselect_all_font_sizes_button->set_icon(get_theme_icon(SNAME("ThemeDeselectAll"), SNAME("EditorIcons")));
			select_all_font_sizes_button->set_icon(get_theme_icon(SNAME("ThemeSelectAll"), SNAME("EditorIcons")));
			select_full_font_sizes_button->set_icon(get_theme_icon(SNAME("ThemeSelectFull"), SNAME("EditorIcons")));
			select_icons_icon->set_texture(get_theme_icon(SNAME("ImageTexture"), SNAME("EditorIcons")));
			deselect_all_icons_button->set_icon(get_theme_icon(SNAME("ThemeDeselectAll"), SNAME("EditorIcons")));
			select_all_icons_button->set_icon(get_theme_icon(SNAME("ThemeSelectAll"), SNAME("EditorIcons")));
			select_full_icons_button->set_icon(get_theme_icon(SNAME("ThemeSelectFull"), SNAME("EditorIcons")));
			select_styleboxes_icon->set_texture(get_theme_icon(SNAME("StyleBoxFlat"), SNAME("EditorIcons")));
			deselect_all_styleboxes_button->set_icon(get_theme_icon(SNAME("ThemeDeselectAll"), SNAME("EditorIcons")));
			select_all_styleboxes_button->set_icon(get_theme_icon(SNAME("ThemeSelectAll"), SNAME("EditorIcons")));
			select_full_styleboxes_button->set_icon(get_theme_icon(SNAME("ThemeSelectFull"), SNAME("EditorIcons")));
		} break;
	}
}
void ThemeItemImportTree::_bind_methods() {
	ADD_SIGNAL(MethodInfo("items_imported"));
}
ThemeItemImportTree::ThemeItemImportTree() {