fix analyze error (#2611)

diff --git a/.ci/flutter_master.version b/.ci/flutter_master.version
index 8fef684..1da87c3 100644
--- a/.ci/flutter_master.version
+++ b/.ci/flutter_master.version
@@ -1 +1 @@
-9c0901ed63d036f73fdf52ca9cf485149b56f798
+7714a8d034ad418bcfcf421e12f45f121c356948
diff --git a/packages/go_router/test/test_helpers.dart b/packages/go_router/test/test_helpers.dart
index 78be1eb..71fb55ae 100644
--- a/packages/go_router/test/test_helpers.dart
+++ b/packages/go_router/test/test_helpers.dart
@@ -350,6 +350,11 @@
 
   @override
   Widget get widget => throw UnimplementedError();
+
+  @override
+  // TODO(bparrishMines): Remove once this parameter is available on Flutter stable.
+  // ignore: override_on_non_overriding_member
+  bool get mounted => throw UnimplementedError();
 }
 
 class DummyStatefulWidget extends StatefulWidget {