### 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.
scene_tabs_context_menu->add_shortcut(ED_GET_SHORTCUT("editor/reopen_closed_scene"), FILE_OPEN_PREV);
				scene_tabs_context_menu->set_item_text(scene_tabs_context_menu->get_item_index(FILE_OPEN_PREV), TTR("Undo Close Tab"));
				if (previous_scenes.is_empty()) {
					scene_tabs_context_menu->set_item_disabled(scene_tabs_context_menu->get_item_index(FILE_OPEN_PREV), true);
				}
				scene_tabs_context_menu->add_item(TTR("Close Other Tabs"), FILE_CLOSE_OTHERS);
				scene_tabs_context_menu->add_item(TTR("Close Tabs to the Right"), FILE_CLOSE_RIGHT);
				scene_tabs_context_menu->add_item(TTR("Close All Tabs"), FILE_CLOSE_ALL);
			}
			scene_tabs_context_menu->set_position(scene_tabs->get_screen_position() + mb->get_position());
			scene_tabs_context_menu->reset_size();
			scene_tabs_context_menu->popup();
		}
	}
}
void EditorNode::_reposition_active_tab(int idx_to) {
	editor_data.move_edited_scene_to_index(idx_to);
	_update_scene_tabs();
}
void EditorNode::_thumbnail_done(const String &p_path, const Ref<Texture2D> &p_preview, const Ref<Texture2D> &p_small_preview, const Variant &p_udata) {
	int p_tab = p_udata.operator signed int();
	if (p_preview.is_valid()) {
		Rect2 rect = scene_tabs->get_tab_rect(p_tab);
		rect.position += scene_tabs->get_global_position();
		tab_preview->set_texture(p_preview);
		tab_preview_panel->set_position(rect.position + Vector2(0, rect.size.height));
		tab_preview_panel->show();
	}
}
void EditorNode::_scene_tab_changed(int p_tab) {