### 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 (InspectorDock::get_inspector_singleton()) {
		InspectorDock::get_inspector_singleton()->update_tree();
	}
}
void EditorNode::_editor_select_next() {
	int editor = _get_current_main_editor();
	do {
		if (editor == editor_table.size() - 1) {
			editor = 0;
		} else {
			editor++;
		}
	} while (!main_editor_buttons[editor]->is_visible());
	editor_select(editor);
}
void EditorNode::_open_command_palette() {
	command_palette->open_popup();
}
void EditorNode::_editor_select_prev() {
	int editor = _get_current_main_editor();
	do {
		if (editor == 0) {
			editor = editor_table.size() - 1;
		} else {
			editor--;
		}
	} while (!main_editor_buttons[editor]->is_visible());
	editor_select(editor);
}
Error EditorNode::load_resource(const String &p_resource, bool p_ignore_broken_deps) {