### 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.
ProjectSettings::get_singleton()->setup(ProjectSettings::get_singleton()->get_resource_path(), String(), true);
	settings_changed = true;
}
void EditorNode::_vp_resized() {
}
void EditorNode::_titlebar_resized() {
	DisplayServer::get_singleton()->window_set_window_buttons_offset(Vector2i(title_bar->get_global_position().y + title_bar->get_size().y / 2, title_bar->get_global_position().y + title_bar->get_size().y / 2), DisplayServer::MAIN_WINDOW_ID);
	const Vector3i &margin = DisplayServer::get_singleton()->window_get_safe_title_margins(DisplayServer::MAIN_WINDOW_ID);
	if (left_menu_spacer) {
		int w = (gui_base->is_layout_rtl()) ? margin.y : margin.x;
		left_menu_spacer->set_custom_minimum_size(Size2(w, 0));
	}
	if (right_menu_spacer) {
		int w = (gui_base->is_layout_rtl()) ? margin.x : margin.y;
		right_menu_spacer->set_custom_minimum_size(Size2(w, 0));
	}
	if (title_bar) {
		title_bar->set_custom_minimum_size(Size2(0, margin.z - title_bar->get_global_position().y));
	}
}
void EditorNode::_version_button_pressed() {
	DisplayServer::get_singleton()->clipboard_set(version_btn->get_meta(META_TEXT_TO_COPY));
}
void EditorNode::_update_undo_redo_allowed() {
	EditorUndoRedoManager *undo_redo = EditorUndoRedoManager::get_singleton();
	file_menu->set_item_disabled(file_menu->get_item_index(EDIT_UNDO), !undo_redo->has_undo());
	file_menu->set_item_disabled(file_menu->get_item_index(EDIT_REDO), !undo_redo->has_redo());
}
void EditorNode::_node_renamed() {