Repository: flutter
Issue: [DataTable] Border path is not complete when borderRadius is added to `TableBorder.symmetric`
Labels: framework,f: material design,has reproducible steps,P2,team-design,triaged-design,found in release: 3.22,found in release: 3.24

### Steps to reproduce

View code examples

### Expected results

Keep rounded borders

### Actual results

dataTable When setting outside borders, rounded borders are lost

### Code sample

```
import 'package:flutter/material.dart';

/// Flutter code sample for [DataTable].

void main() => runApp(const DataTableExampleApp());

class DataTableExampleApp extends StatelessWidget {
  const DataTableExampleApp({super.key});

  @override
  Widget build(BuildContext context) {
    return MaterialApp(
      home: Scaffold(
        appBar: AppBar(title: const Text('DataTable Sample')),
        body: const DataTableExample(),
      ),
    );
  }
}

class DataTableExample extends StatelessWidget {
  const DataTableExample({super.key});

  @override
  Widget build(BuildContext context) {
    return DataTable(
      clipBehavior: Clip.hardEdge,
      border: TableBorder.symmetric(
        outside: const BorderSide(color: Colors.red),
        borderRadius: BorderRadius.circular(15),
      ),
      columns: const <DataColumn>[
        DataColumn(
          label: Expanded(
            child: Text(
              'Name',
              style: TextStyle(fontStyle: FontStyle.italic),
            ),
          ),
        ),
        DataColumn(
          label: Expanded(
            child: Text(
              'Age',
              style: TextStyle(fontStyle: FontStyle.italic),
            ),
          ),
        ),
        DataColumn(
          label: Expanded(
            child: Text(
              'Role',
              style: TextStyle(fontStyle: FontStyle.italic),
            ),
          ),
        ),
      ],
      rows: const <DataRow>[
        DataRow(
          cells: <DataCell>[
            DataCell(Text('Sarah')),
            DataCell(Text('19')),
            DataCell(Text('Student')),
          ],
        ),
        DataRow(
          cells: <DataCell>[
            DataCell(Text('Janine')),
            DataCell(Text('43')),
            DataCell(Text('Professor')),
          ],
        ),
        DataRow(
          cells: <DataCell>[
            DataCell(Text('William')),
            DataCell(Text('27')),
            DataCell(Text('Associate Professor')),
          ],
        ),
      ],
    );
  }
}

```

### Screenshots or Video

![image](https://github.com/user-attachments/assets/7aa7d558-2a56-4867-b552-0a204bdd65ae)

### Logs

<details open><summary>Logs</summary>

```console
[Paste your logs here]
```

</details>


### Flutter Doctor output

```
[√] Flutter (Channel stable, 3.22.3, on Microsoft Windows [ 10.0.19045.2965], locale zh-CN)
    • Flutter version 3.22.3 on channel stable at E:\flutter\versions\stable
    • Upstream repository https://github.com/flutter/flutter.git
    • Framework revision b0850beeb2 (2 weeks ago), 2024-07-16 21:43:41 -0700
    • Engine revision 235db911ba
    • Dart version 3.4.4
    • DevTools version 2.34.3

[√] Windows Version (Installed version of Windows is version 10 or higher)

[!] Android toolchain - develop for Android devices (Android SDK version 34.0.0)
    • Android SDK at E:\android-sdk
    • Platform android-34, build-tools 34.0.0
    • ANDROID_HOME = E:\android-sdk
    • ANDROID_SDK_ROOT = E:\android-sdk
    • Java binary at: E:\android-studio\jbr\bin\java
    • Java version OpenJDK Runtime Environment (build 17.0.10+0--11609105)
    ! Some Android licenses not accepted. To resolve this, run: flutter doctor --android-licenses

[√] Chrome - develop for the web
    • Chrome at C:\Program Files\Google\Chrome\Application\chrome.exe

[√] Visual Studio - develop Windows apps (Visual Studio Community 2022 17.10.4)
    • Visual Studio at D:\Visual Studio
    • Visual Studio Community 2022 version 17.10.35027.167
    • Windows 10 SDK version 10.0.22621.0

[√] Android Studio (version 2024.1)
    • Android Studio at E:\android-studio
    • 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
    • Java version OpenJDK Runtime Environment (build 17.0.10+0--11609105)
```