### Godot version

v4.0.beta.custom_build [fab9926a9]

### System information

Fedora 37

### Issue description

When creating a new inherited scene, saving the scene (for example with Ctrl+S) defaults to overwriting the scene being inherited, instead of prompting for a location to save to.

### Steps to reproduce

1. Create a new inherited scene
2. Press Ctrl+S

If the scene being inherited is imported (for example from a glTF), an error displays. If the inherited scene is a .tscn or .scn, it gets overridden by an inherited scene that tries to inherit itself, which is impossible and thus corrupt.

### Minimal reproduction project

N/A
if (waiting_for_first_scan) {
		waiting_for_first_scan = false;
		Engine::get_singleton()->startup_benchmark_end_measure(); 
		
		
		RenderingServer::get_singleton()->global_shader_parameters_load_settings(true);
		
		if (!singleton->cmdline_export_mode) {
			EditorResourcePreview::get_singleton()->start();
		}
		_load_docks();
		if (!defer_load_scene.is_empty()) {
			Engine::get_singleton()->startup_benchmark_begin_measure("editor_load_scene");
			load_scene(defer_load_scene);
			defer_load_scene = "";
			Engine::get_singleton()->startup_benchmark_end_measure();
			if (use_startup_benchmark) {
				Engine::get_singleton()->startup_dump(startup_benchmark_file);
				startup_benchmark_file = String();
				use_startup_benchmark = false;
			}
		}
	}
}
void EditorNode::_scan_external_changes() {