### 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 (FileDialog *E : file_dialogs) {
		E->invalidate();
	}
	for (EditorFileDialog *E : editor_file_dialogs) {
		E->invalidate();
	}
	_mark_unsaved_scenes();
	
	String export_error;
	Error err = OK;
	if (!export_defer.preset.is_empty() && !EditorFileSystem::get_singleton()->is_scanning()) {
		String preset_name = export_defer.preset;
		
		
		export_defer.preset = "";
		Ref<EditorExportPreset> export_preset;
		for (int i = 0; i < EditorExport::get_singleton()->get_export_preset_count(); ++i) {
			export_preset = EditorExport::get_singleton()->get_export_preset(i);
			if (export_preset->get_name() == preset_name) {
				break;
			}
			export_preset.unref();