### 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.
EditorPlugin::AfterGUIInput after = EditorPlugin::AFTER_GUI_INPUT_PASS;
	for (int i = 0; i < plugins_list.size(); i++) {
		if ((!serve_when_force_input_enabled) && plugins_list[i]->is_input_event_forwarding_always_enabled()) {
			continue;
		}
		EditorPlugin::AfterGUIInput current_after = plugins_list[i]->forward_3d_gui_input(p_camera, p_event);
		if (current_after == EditorPlugin::AFTER_GUI_INPUT_STOP) {
			after = EditorPlugin::AFTER_GUI_INPUT_STOP;
		}
		if (after != EditorPlugin::AFTER_GUI_INPUT_STOP && current_after == EditorPlugin::AFTER_GUI_INPUT_CUSTOM) {
			after = EditorPlugin::AFTER_GUI_INPUT_CUSTOM;
		}
	}
	return after;
}
void EditorPluginList::forward_canvas_draw_over_viewport(Control *p_overlay) {
	for (int i = 0; i < plugins_list.size(); i++) {
		plugins_list[i]->forward_canvas_draw_over_viewport(p_overlay);
	}
}
void EditorPluginList::forward_canvas_force_draw_over_viewport(Control *p_overlay) {
	for (int i = 0; i < plugins_list.size(); i++) {
		plugins_list[i]->forward_canvas_force_draw_over_viewport(p_overlay);
	}
}
void EditorPluginList::forward_3d_draw_over_viewport(Control *p_overlay) {