[go_router] Rephrases readme to better describe the current status (#8403)

Author: chunhtai

packages/go_router/CHANGELOG.md

@@ -1,3 +1,7 @@
+## 14.6.4
+
+- Rephrases readme.
+
 ## 14.6.3
 
 - Updates minimum supported SDK version to Flutter 3.22/Dart 3.4.

packages/go_router/README.md

@@ -72,6 +72,7 @@ The project follows the same priority system as flutter framework.
 
 ## Roadmap
 
-This package has entered a maintenance phase.  The Flutter team's primary focus will be on
+This package is considered feature-complete.  The Flutter team's primary focus will be on
 addressing bug fixes and ensuring stability.  While active feature development is not currently
-planned, we welcome and encourage community contributions to expand the package's functionality.
+planned, we still welcome and encourage community contributions to expand the package's
+functionality.

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: 14.6.3
+version: 14.6.4
 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