### 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.
Ref<ResourceImporterBMFont> import_font_data_bmfont;
		import_font_data_bmfont.instantiate();
		ResourceFormatImporter::get_singleton()->add_importer(import_font_data_bmfont);
		Ref<ResourceImporterImageFont> import_font_data_image;
		import_font_data_image.instantiate();
		ResourceFormatImporter::get_singleton()->add_importer(import_font_data_image);
		Ref<ResourceImporterCSVTranslation> import_csv_translation;
		import_csv_translation.instantiate();
		ResourceFormatImporter::get_singleton()->add_importer(import_csv_translation);
		Ref<ResourceImporterWAV> import_wav;
		import_wav.instantiate();
		ResourceFormatImporter::get_singleton()->add_importer(import_wav);
		Ref<ResourceImporterOBJ> import_obj;
		import_obj.instantiate();
		ResourceFormatImporter::get_singleton()->add_importer(import_obj);
		Ref<ResourceImporterShaderFile> import_shader_file;
		import_shader_file.instantiate();
		ResourceFormatImporter::get_singleton()->add_importer(import_shader_file);
		Ref<ResourceImporterScene> import_scene;
		import_scene.instantiate();
		ResourceFormatImporter::get_singleton()->add_importer(import_scene);
		Ref<ResourceImporterScene> import_animation;
		import_animation = Ref<ResourceImporterScene>(memnew(ResourceImporterScene(true)));
		ResourceFormatImporter::get_singleton()->add_importer(import_animation);
		{
			Ref<EditorSceneFormatImporterCollada> import_collada;
			import_collada.instantiate();
			ResourceImporterScene::add_importer(import_collada);
			Ref<EditorOBJImporter> import_obj2;
			import_obj2.instantiate();