Fix scrollable TabBar expands to full width when the divider is removed (#140963)
fixes [TabBar Expands to full width of the screen isScrollable: true after upgrading to flutter 3.16.4](https://github.com/flutter/flutter/issues/140338)
---
## Description
Fixes the scrollable `TabBar` width when the divider is removed. (when the divider height is set to `0` or divider color is set to `Colors.transparent`)
### Code sample
<details>
<summary>expand to view the code sample</summary>
```dart
import 'package:flutter/material.dart';
void main() => runApp(const MyApp());
class MyApp extends StatelessWidget {
const MyApp({super.key});
@override
Widget build(BuildContext context) {
const int tabsCount = 2;
return MaterialApp(
home: DefaultTabController(
initialIndex: 1,
length: tabsCount,
child: Scaffold(
appBar: AppBar(
title: const Text('TabBar Sample'),
bottom: PreferredSize(
preferredSize: const Size.fromHeight(48.0),
child: ColoredBox(
color: Theme.of(context).colorScheme.secondaryContainer,
child: TabBar(
// dividerColor: Theme.of(context).colorScheme.onSurface,
dividerColor: Colors.transparent, // remove divider
// dividerHeight: 0, // remove divider
isScrollable: true,
tabAlignment: TabAlignment.center,
tabs: <Widget>[
for (int i = 0; i < tabsCount; i++)
Tab(
text: 'Tab $i',
),
],
),
),
),
),
),
),
);
}
}
```
</details>
### Before
### After
88016c11b4