### 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.
List<StringName> tl;
	theme_base->get_theme()->get_icon_list(SNAME("EditorIcons"), &tl);
	for (const StringName &E : tl) {
		if (!ClassDB::class_exists(E)) {
			continue;
		}
		icon_type_cache[E] = theme_base->get_theme()->get_icon(E, SNAME("EditorIcons"));
	}
}
void EditorNode::_enable_pending_addons() {
	for (uint32_t i = 0; i < pending_addons.size(); i++) {
		set_addon_plugin_enabled(pending_addons[i], true);
	}
	pending_addons.clear();
}
void EditorNode::_file_dialog_register(FileDialog *p_dialog) {