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Fix RangeSlider renders track when track colors are transparent (#162386 )

### Description 

Fixes [`Slider` with transparent track colors and custom `trackHeight`
cannot reach the extreme
ends](https://github.com/flutter/flutter/issues/161210) but for
`RangeSlider`.

### 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 StatefulWidget {
  const MyApp({super.key});

  @override
  State<MyApp> createState() => _MyAppState();
}

class _MyAppState extends State<MyApp> {
  RangeValues _values = const RangeValues(0, 100);

  @override
  Widget build(BuildContext context) {
    return MaterialApp(
      debugShowCheckedModeBanner: false,
      home: Scaffold(
        body: Center(
          child: Column(
            spacing: 20,
            mainAxisSize: MainAxisSize.min,
            children: <Widget>[
              SliderTheme(
                data: const SliderThemeData(
                  trackHeight: 100,
                  activeTrackColor: Colors.transparent,
                  inactiveTrackColor: Colors.transparent,
                ),
                child: RangeSlider(
                  values: _values,
                  max: 100,
                  onChanged: (RangeValues values) {
                    setState(() {
                      _values = values;
                    });
                  },
                ),
              ),
            ],
          ),
        ),
      ),
    );
  }
}

```

</details>


### Before

<img width="755" alt="Screenshot 2025-02-12 at 15 56 21"
src="https://github.com/user-attachments/assets/e8c88bd8-3c87-46e2-9f29-b945128ae93a"
/>


### After

<img width="755" alt="Screenshot 2025-02-12 at 15 56 09"
src="https://github.com/user-attachments/assets/5f9244e8-4d51-40f3-a3fc-afdf9dff9b35"
/>


## Pre-launch Checklist

- [x] I read the [Contributor Guide] and followed the process outlined
there for submitting PRs.
- [x] I read the [Tree Hygiene] wiki page, which explains my
responsibilities.
- [x] I read and followed the [Flutter Style Guide], including [Features
we expect every widget to implement].
- [x] I signed the [CLA].
- [x] I listed at least one issue that this PR fixes in the description
above.
- [x] I updated/added relevant documentation (doc comments with `///`).
- [x] I added new tests to check the change I am making, or this PR is
[test-exempt].
- [ ] I followed the [breaking change policy] and added [Data Driven
Fixes] where supported.
- [x] All existing and new tests are passing.

If you need help, consider asking for advice on the #hackers-new channel
on [Discord].

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[Data Driven Fixes]:
https://github.com/flutter/flutter/blob/main/docs/contributing/Data-driven-Fixes.md