### Godot version

master

### System information

Godot v4.2.beta (0ea75d77c) - Windows 10.0.22621 - Vulkan (Forward+) - dedicated NVIDIA GeForce RTX 2070 (NVIDIA; 31.0.15.3598) - Intel(R) Core(TM) i7-10750H CPU @ 2.60GHz (12 Threads)

### Issue description

When any of the Import, Filesystem, Node, or History docks are floating, changing an editor feature crashes the engine.
Changing any setting or selecting a different profile triggers it.

This is because `EditorNode::_feature_profile_changed` assumes the docks are in a `TabContainer`, and if they are floating they aren't in one.


### Steps to reproduce

Make any of these docks floating: Import, Filesystem, Node, or History
Open Editor Features (Editor -> Manage Editor Features...)
Make a profile (if you have none) or change a setting on the existing profile

### Minimal reproduction project

n/a
if (p_idx == 0) { 
		current_menu_option = FILE_EXPORT_MESH_LIBRARY;
		if (!editor_data.get_edited_scene_root()) {
			show_accept(TTR("This operation can't be done without a scene."), TTR("OK"));
			return;
		}
		List<String> extensions;
		Ref<MeshLibrary> ml(memnew(MeshLibrary));
		ResourceSaver::get_recognized_extensions(ml, &extensions);
		file_export_lib->clear_filters();
		for (const String &E : extensions) {
			file_export_lib->add_filter("*." + E);
		}
		file_export_lib->popup_file_dialog();
		file_export_lib->set_title(TTR("Export Mesh Library"));
	} else { 
		if (export_as_menu->get_item_submenu(p_idx).is_empty()) { 
			Callable callback = export_as_menu->get_item_metadata(p_idx);
			Callable::CallError ce;
			Variant result;
			callback.callp(nullptr, 0, result, ce);
			if (ce.error != Callable::CallError::CALL_OK) {
				String err = Variant::get_callable_error_text(callback, nullptr, 0, ce);
				ERR_PRINT("Error calling function from export_as menu: " + err);
			}
		}
	}
}
int EditorNode::_next_unsaved_scene(bool p_valid_filename, int p_start) {