[navigator2.0] Memory leak when remove page that not on the top of the stack

Steps to reproduce

build pages stack(a->b->c) use navigator pages api
go to page c, snapshot memory use devtools
at page c, add and remove page b many times
snapshot memory again, diff with step2

Expected results

page b instance count is none or one

Actual results

all page b instance retained by "Isolate → WidgetsFlutterBinding → BuildOwner " and not released

Code sample

```dart @override Widget build(BuildContext context) { List pages = [ MaterialPage( key: ValueKey('VeggiesListPage'), child: VeggiesListScreen( veggies: veggies, onTapped: _handleVeggieTapped, ), ), // this page leaks when add and remove repeatedly if (show404) MaterialPage(key: ValueKey('UnknownPage'), child: UnknownScreen()), if (_selectedVeggie != null) MaterialPage( key: ValueKey(_selectedVeggie!), child: VeggieDetailsScreen( veggie: _selectedVeggie!, show: show404, onTapped: () { show404 = !show404; notifyListeners(); }, ), ), ]; return Navigator( key: navigatorKey, pages: pages, onPopPage: (route, result) { if (!route.didPop(result)) { return false; } // Update the list of pages by setting _selectedVeggie to null _selectedVeggie = null; show404 = false; notifyListeners(); return true; }, ); } ``` [flutter_navigator_v2-master.zip](https://github.com/user-attachments/files/16244074/flutter_navigator_v2-master.zip)

Screenshots or Video

Screenshots / Video demonstration

[Upload media here] https://github.com/user-attachments/assets/c8058a8e-cd3e-4a48-b4a2-c03d3ff7ee64

Logs

leaks detail: [snapshot_diff.csv](https://github.com/user-attachments/files/16244492/snapshot_diff.csv)

Flutter Doctor output

Doctor output

```console flutter doctor Doctor summary (to see all details, run flutter doctor -v): [✓] Flutter (Channel stable, 3.22.2, on macOS 14.4.1 23E224 darwin-x64, locale zh-Hans-CN) [✓] Android toolchain - develop for Android devices (Android SDK version 33.0.2) [✓] Xcode - develop for iOS and macOS (Xcode 15.3) [✓] Chrome - develop for the web [✓] Android Studio (version 2022.3) [✓] VS Code (version 1.91.0) [✓] Connected device (3 available) ! Error: Browsing on the local area network for iPhone (205). Ensure the device is unlocked and attached with a cable or associated with the same local area network as this Mac. The device must be opted into Developer Mode to connect wirelessly. (code -27) ! Error: Browsing on the local area network for iPhone. Ensure the device is unlocked and attached with a cable or associated with the same local area network as this Mac. The device must be opted into Developer Mode to connect wirelessly. (code -27) ! Error: Browsing on the local area network for zhu的iPad. Ensure the device is unlocked and attached with a cable or associated with the same local area network as this Mac. The device must be opted into Developer Mode to connect wirelessly. (code -27) ! Error: Browsing on the local area network for lin he的iPhone. Ensure the device is unlocked and attached with a cable or associated with the same local area network as this Mac. The device must be opted into Developer Mode to connect wirelessly. (code -27) [✓] Network resources • No issues found! ```

Thanks for the report. I can observe the same on Devtools. I also see no instance has been released as well:

Screenshot 2024-07-16 at 12 12 42

flutter doctor -v (stable and master)

```bash [✓] Flutter (Channel stable, 3.22.2, on macOS 14.1 23B74 darwin-x64, locale en-VN) • Flutter version 3.22.2 on channel stable at /Users/huynq/Documents/GitHub/flutter • Upstream repository https://github.com/flutter/flutter.git • Framework revision 761747bfc5 (3 weeks ago), 2024-06-05 22:15:13 +0200 • Engine revision edd8546116 • Dart version 3.4.3 • DevTools version 2.34.3 [✓] Android toolchain - develop for Android devices (Android SDK version 34.0.0) • Android SDK at /Users/huynq/Library/Android/sdk • Platform android-34, build-tools 34.0.0 • ANDROID_HOME = /Users/huynq/Library/Android/sdk • Java binary at: /Applications/Android Studio.app/Contents/jbr/Contents/Home/bin/java • Java version OpenJDK Runtime Environment (build 17.0.10+0-17.0.10b1087.21-11572160) • All Android licenses accepted. [✓] Xcode - develop for iOS and macOS (Xcode 15.4) • Xcode at /Applications/Xcode15.4.app/Contents/Developer • Build 15F31d • CocoaPods version 1.15.2 [✓] Chrome - develop for the web • Chrome at /Applications/Google Chrome.app/Contents/MacOS/Google Chrome [✓] Android Studio (version 2023.3) • Android Studio at /Applications/Android Studio.app/Contents • Flutter plugin can be installed from: 🔨 https://plugins.jetbrains.com/plugin/9212-flutter • Dart plugin can be installed from: 🔨 https://plugins.jetbrains.com/plugin/6351-dart • android-studio-dir = /Applications/Android Studio.app/ • Java version OpenJDK Runtime Environment (build 17.0.10+0-17.0.10b1087.21-11572160) [✓] VS Code (version 1.90.2) • VS Code at /Applications/Visual Studio Code.app/Contents • Flutter extension version 3.90.0 [✓] Connected device (3 available) • iPhone (mobile) • d9a94afe2b649fef56ba0bfeb052f0f2a7dae95e • ios • iOS 15.8 19H370 • macOS (desktop) • macos • darwin-x64 • macOS 14.1 23B74 darwin-x64 • Chrome (web) • chrome • web-javascript • Google Chrome 126.0.6478.127 [✓] Network resources • All expected network resources are available. • No issues found! ``` ```bash [!] Flutter (Channel master, 3.24.0-1.0.pre.129, on macOS 14.1 23B74 darwin-x64, locale en-VN) • Flutter version 3.24.0-1.0.pre.129 on channel master at /Users/huynq/Documents/GitHub/flutter_master ! Warning: `flutter` on your path resolves to /Users/huynq/Documents/GitHub/flutter/bin/flutter, which is not inside your current Flutter SDK checkout at /Users/huynq/Documents/GitHub/flutter_master. Consider adding /Users/huynq/Documents/GitHub/flutter_master/bin to the front of your path. ! Warning: `dart` on your path resolves to /Users/huynq/Documents/GitHub/flutter/bin/dart, which is not inside your current Flutter SDK checkout at /Users/huynq/Documents/GitHub/flutter_master. Consider adding /Users/huynq/Documents/GitHub/flutter_master/bin to the front of your path. • Upstream repository https://github.com/flutter/flutter.git • Framework revision 0a99e1f9a9 (87 minutes ago), 2024-07-16 00:57:11 -0400 • Engine revision 2e4401545c • Dart version 3.6.0 (build 3.6.0-36.0.dev) • DevTools version 2.37.1 • If those were intentional, you can disregard the above warnings; however it is recommended to use "git" directly to perform update checks and upgrades. [✓] Android toolchain - develop for Android devices (Android SDK version 34.0.0) • Android SDK at /Users/huynq/Library/Android/sdk • Platform android-34, build-tools 34.0.0 • ANDROID_HOME = /Users/huynq/Library/Android/sdk • Java binary at: /Applications/Android Studio.app/Contents/jbr/Contents/Home/bin/java • Java version OpenJDK Runtime Environment (build 17.0.10+0-17.0.10b1087.21-11572160) • All Android licenses accepted. [✓] Xcode - develop for iOS and macOS (Xcode 15.4) • Xcode at /Applications/Xcode15.4.app/Contents/Developer • Build 15F31d • CocoaPods version 1.15.2 [✓] Chrome - develop for the web • Chrome at /Applications/Google Chrome.app/Contents/MacOS/Google Chrome [✓] Android Studio (version 2023.3) • Android Studio at /Applications/Android Studio.app/Contents • Flutter plugin can be installed from: 🔨 https://plugins.jetbrains.com/plugin/9212-flutter • Dart plugin can be installed from: 🔨 https://plugins.jetbrains.com/plugin/6351-dart • android-studio-dir = /Applications/Android Studio.app/ • Java version OpenJDK Runtime Environment (build 17.0.10+0-17.0.10b1087.21-11572160) [✓] VS Code (version 1.91.0) • VS Code at /Applications/Visual Studio Code.app/Contents • Flutter extension version 3.92.0 [✓] Connected device (2 available) • macOS (desktop) • macos • darwin-x64 • macOS 14.1 23B74 darwin-x64 • Chrome (web) • chrome • web-javascript • Google Chrome 126.0.6478.127 [✓] Network resources • All expected network resources are available. ! Doctor found issues in 1 category. ```

flutter / flutter