### 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.
ERR_FAIL_COND_V(!p_object, StringName());
	Ref<Script> scr = p_object->get_script();
	if (scr.is_null() && Object::cast_to<Script>(p_object)) {
		scr = p_object;
	}
	if (scr.is_valid()) {
		Ref<Script> base_scr = scr;
		while (base_scr.is_valid()) {
			StringName name = EditorNode::get_editor_data().script_class_get_name(base_scr->get_path());
			if (name != StringName()) {
				return name;
			}
			
			StringName base = base_scr->get_instance_base_type();
			if (base != StringName() && EditorNode::get_editor_data().get_custom_types().has(base)) {
				const Vector<EditorData::CustomType> &types = EditorNode::get_editor_data().get_custom_types()[base];
				for (int i = 0; i < types.size(); ++i) {
					if (types[i].script == base_scr) {
						return types[i].name;
					}
				}
			}
			base_scr = base_scr->get_base_script();
		}
	}
	return StringName();
}
void EditorNode::_pick_main_scene_custom_action(const String &p_custom_action_name) {