[go_router] Update sype safe routing topic to use mixin from go_router_builder 3.0.0 (#9422)

Fixes flutter/flutter#170574

## Pre-Review Checklist

[^1]: Regular contributors who have demonstrated familiarity with the repository guidelines only need to comment if the PR is not auto-exempted by repo tooling.

Author: ValentinVignal

packages/go_router/CHANGELOG.md

@@ -1,3 +1,7 @@
+## 15.2.3
+
+- Updates Type-safe routes topic documentation to use the mixin from `go_router_builder` 3.0.0.
+
 ## 15.2.2
 
 - Fixes calling `PopScope.onPopInvokedWithResult` in branch routes.

packages/go_router/doc/type-safe-routes.md

@@ -1,5 +1,5 @@
 Instead of using URL strings to navigate, go_router supports
-type-safe routes using the go_router_builder package. 
+type-safe routes using the go_router_builder package.
 
 To get started, add [go_router_builder][], [build_runner][], and
 [build_verify][] to the dev_dependencies section of your pubspec.yaml:
@@ -28,15 +28,15 @@ part 'go_router_builder.g.dart';
     ]
 )
 @immutable
-class HomeScreenRoute extends GoRouteData {
+class HomeScreenRoute extends GoRouteData with _$HomeScreenRoute {
   @override
   Widget build(BuildContext context, GoRouterState state) {
     return const HomeScreen();
   }
 }
 
 @immutable
-class SongRoute extends GoRouteData {
+class SongRoute extends GoRouteData with _$SongRoute {
   final int id;
 
   const SongRoute({
@@ -74,4 +74,4 @@ package documentation](https://pub.dev/documentation/go_router_builder/latest/).
 
 [go_router_builder]: https://pub.dev/packages/go_router_builder
 [build_runner]: https://pub.dev/packages/build_runner
-[build_verify]: https://pub.dev/packages/build_verify
+[build_verify]: https://pub.dev/packages/build_verify

packages/go_router/pubspec.yaml

@@ -1,7 +1,7 @@
 name: go_router
 description: A declarative router for Flutter based on Navigation 2 supporting
   deep linking, data-driven routes and more
-version: 15.2.2
+version: 15.2.3
 repository: https://github.com/flutter/packages/tree/main/packages/go_router
 issue_tracker: https://github.com/flutter/flutter/issues?q=is%3Aissue+is%3Aopen+label%3A%22p%3A+go_router%22