Repository: flutter
Issue: Flutter on Linux desktop: Neo2 Keyboard Layout not all keys recognized (missing e.g.: Arrows, Delete, Insert, ...)
Labels: a: text input,platform-linux,a: desktop,P2,team-linux,triaged-linux

### Steps to reproduce

Not all layer 4 keys of the neo2 keyboard layout are working on flutter on linux desktop. The same code works on linux in a web browser correctly: 

1. Create any flutter desktop app having a text input
2. Switch the keyboard layout to neo2 https://www.neo-layout.org/
3. Open app and type text and try e.g. to move with arrow keys (or try other layer 4 keys, M4 + key)

Comparison: Linux desktop vs. Linux in browser (Both show Arrow Down keypress):
![Screenshot from 2023-12-30 18-57-09](https://github.com/flutter/flutter/assets/9157720/5e086174-6458-41bc-8aa8-e1f7030ff08b)

In all other applications keys are handled correctly (gtk/Qt/...)

### Expected results

All keys of layer 4 (M4 + Key) are working correctly

### Actual results

Some keys of layer 4 are not working: (green works, red works not)
![neo2_flutter_desktop_missing_keys](https://github.com/flutter/flutter/assets/9157720/679695ea-200c-42b8-a30d-da19f2c80df8)


### Code sample

<details open><summary>Code sample</summary>

```dart
import 'dart:io';

import 'package:flutter/foundation.dart';
import 'package:flutter/material.dart';
import 'package:flutter/services.dart';

void main() {
  // See https://github.com/flutter/flutter/wiki/Desktop-shells#target-platform-override
  if (!kIsWeb && (Platform.isLinux || Platform.isWindows)) {
    debugDefaultTargetPlatformOverride = TargetPlatform.fuchsia;
  }
  runApp(MyApp());
}

class MyApp extends StatelessWidget {
  @override
  Widget build(BuildContext context) {
    return MaterialApp(
      debugShowCheckedModeBanner: false,
      home: Scaffold(
        body: RawKeyboardListener(
          child: TextField(),
          focusNode: FocusNode(),
          onKey: (event) async {
            if (event.runtimeType == RawKeyDownEvent) {
              print(
                  'id: ${event.logicalKey.keyId}, label: ${event.logicalKey.keyLabel} debugName: ${event.logicalKey.debugName}');
            }
          },
        ),
      ),
    );
  }
}
```

</details>


### Screenshots or Video

<details open>
<summary>Screenshots / Video demonstration</summary>

![howto3](https://github.com/flutter/flutter/assets/9157720/6f34039c-1036-4181-99ca-3c5bcd824c0d)

</details>


### Logs

<details open><summary>Logs</summary>

```console
[Paste your logs here]
```

</details>


### Flutter Doctor output

<details open><summary>Doctor output</summary>

```console
Doctor summary (to see all details, run flutter doctor -v):
[✓] Flutter (Channel beta, 3.18.0-0.2.pre, on Ubuntu 22.04.3 LTS
    6.2.0-39-generic, locale en_US.UTF-8)
[✓] Android toolchain - develop for Android devices (Android SDK version 34.0.0)
[✗] Chrome - develop for the web (Cannot find Chrome executable at
    google-chrome)
    ! Cannot find Chrome. Try setting CHROME_EXECUTABLE to a Chrome executable.
[✓] Linux toolchain - develop for Linux desktop
[✓] Android Studio (version 2023.1)
[✓] VS Code (version 1.85.1)
[✓] Connected device (1 available)
[✓] Network resources

! Doctor found issues in 1 category.

```

</details>