### 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.
for (int i = 0; i < bottom_panel_items.size(); i++) {
		if (bottom_panel_items[i].control == p_item) {
			if (p_item->is_visible_in_tree()) {
				_bottom_panel_switch(false, i);
			}
			bottom_panel_vb->remove_child(bottom_panel_items[i].control);
			bottom_panel_hb_editors->remove_child(bottom_panel_items[i].button);
			memdelete(bottom_panel_items[i].button);
			bottom_panel_items.remove_at(i);
			break;
		}
	}
	for (int i = 0; i < bottom_panel_items.size(); i++) {
		bottom_panel_items[i].button->disconnect("toggled", callable_mp(this, &EditorNode::_bottom_panel_switch));
		bottom_panel_items[i].button->connect("toggled", callable_mp(this, &EditorNode::_bottom_panel_switch).bind(i));
	}
}
void EditorNode::_bottom_panel_switch(bool p_enable, int p_idx) {
	if (bottom_panel_updating) {
		return;
	}
	ERR_FAIL_INDEX(p_idx, bottom_panel_items.size());
	if (bottom_panel_items[p_idx].control->is_visible() == p_enable) {
		return;
	}
	if (p_enable) {