### 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.
if (!bool(EDITOR_GET("interface/scene_tabs/show_thumbnail_on_hover"))) {
		return;
	}
	int current_tab = scene_tabs->get_current_tab();
	if (p_tab == current_tab || p_tab < 0) {
		tab_preview_panel->hide();
	} else {
		String path = editor_data.get_scene_path(p_tab);
		if (!path.is_empty()) {
			EditorResourcePreview::get_singleton()->queue_resource_preview(path, this, "_thumbnail_done", p_tab);
		}
	}
}
void EditorNode::_scene_tab_exit() {
	tab_preview_panel->hide();
}
void EditorNode::_scene_tab_input(const Ref<InputEvent> &p_input) {