### 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.
singleton->file_dialogs.insert(p_dialog);
}
void EditorNode::_file_dialog_unregister(FileDialog *p_dialog) {
	singleton->file_dialogs.erase(p_dialog);
}
void EditorNode::_editor_file_dialog_register(EditorFileDialog *p_dialog) {
	singleton->editor_file_dialogs.insert(p_dialog);
}
void EditorNode::_editor_file_dialog_unregister(EditorFileDialog *p_dialog) {
	singleton->editor_file_dialogs.erase(p_dialog);
}
Vector<EditorNodeInitCallback> EditorNode::_init_callbacks;
void EditorNode::_begin_first_scan() {
	OS::get_singleton()->benchmark_begin_measure("editor_scan_and_import");
	EditorFileSystem::get_singleton()->scan();
}
Error EditorNode::export_preset(const String &p_preset, const String &p_path, bool p_debug, bool p_pack_only) {
	export_defer.preset = p_preset;
	export_defer.path = p_path;
	export_defer.debug = p_debug;
	export_defer.pack_only = p_pack_only;
	cmdline_export_mode = true;
	return OK;
}
void EditorNode::show_accept(const String &p_text, const String &p_title) {