### Godot version

4.1.beta (7b1387ff2)

### System information

Mageia 9, Linux

### Issue description

When opening an empty project in latest `master`, I get these errors:
```
ERROR: Index p_idx = -1 is out of bounds (edited_scene.size() = 1).
   at: get_scene_path (editor/scu/../editor_data.cpp:880)
ERROR: Index p_idx = -1 is out of bounds (edited_scene.size() = 1).
   at: check_and_update_scene (editor/scu/../editor_data.cpp:683)
ERROR: Index p_idx = -1 is out of bounds (edited_scene.size() = 1).
   at: set_edited_scene (editor/scu/../editor_data.cpp:745)
```

Possibly related to recent changes to restore past sessions, but there's nothing to restore in this case?

### Steps to reproduce

- Create a new project, edit it
- Quit to project manager
- Re-open the newly created project -> errors

### Minimal reproduction project

Empty project.
p_layout->set_value(p_section, "dock_split_" + itos(i + 1), vsplits[i]->get_split_offset());
		}
	}
	for (int i = 0; i < hsplits.size(); i++) {
		p_layout->set_value(p_section, "dock_hsplit_" + itos(i + 1), hsplits[i]->get_split_offset());
	}
	
	p_layout->set_value(p_section, "dock_filesystem_split", FileSystemDock::get_singleton()->get_split_offset());
	p_layout->set_value(p_section, "dock_filesystem_display_mode", FileSystemDock::get_singleton()->get_display_mode());
	p_layout->set_value(p_section, "dock_filesystem_file_sort", FileSystemDock::get_singleton()->get_file_sort());
	p_layout->set_value(p_section, "dock_filesystem_file_list_display_mode", FileSystemDock::get_singleton()->get_file_list_display_mode());
	PackedStringArray selected_files = FileSystemDock::get_singleton()->get_selected_paths();
	p_layout->set_value(p_section, "dock_filesystem_selected_paths", selected_files);
	Vector<String> uncollapsed_paths = FileSystemDock::get_singleton()->get_uncollapsed_paths();
	p_layout->set_value(p_section, "dock_filesystem_uncollapsed_paths", uncollapsed_paths);
}
void EditorNode::_save_open_scenes_to_config(Ref<ConfigFile> p_layout) {
	PackedStringArray scenes;
	for (int i = 0; i < editor_data.get_edited_scene_count(); i++) {
		String path = editor_data.get_scene_path(i);
		if (path.is_empty()) {
			continue;
		}
		scenes.push_back(path);
	}
	p_layout->set_value(EDITOR_NODE_CONFIG_SECTION, "open_scenes", scenes);
	String currently_edited_scene_path = editor_data.get_scene_path(editor_data.get_edited_scene());
	p_layout->set_value(EDITOR_NODE_CONFIG_SECTION, "current_scene", currently_edited_scene_path);
}
void EditorNode::save_editor_layout_delayed() {