[Bug]: Infinite loading when using the progress bar / +10 -10 buttons

When using the chewie video player and using the progress bar / +10 -10 buttons, an infinite loader appears and never wants to disappear.

Usage :
```
ChewieController(
videoPlayerController: _controller!,
looping: true, // Because there is a bug of infinite loader (https://github.com/fluttercommunity/chewie/issues/906)
customControls: CupertinoControls(
backgroundColor: Colors.grey,
iconColor: Colors.white,
),
)

Chewie(controller: _chewieController!)
```
Actions :

```
- I play the video
- I scroll the video progress bar to the right / left OR I use the +10 -10 buttons
-> An infinite loader appears
```

Package version : `chewie: ^1.11.0`

Flutter doctor :
```
[✓] Flutter (Channel stable, 3.29.2, on macOS 15.3.1 24D70 darwin-arm64, locale en-MX) [2.9s]
• Flutter version 3.29.2 on channel stable at /Users/da2ny/development/flutter
• Upstream repository https://github.com/flutter/flutter.git
• Framework revision c236373904 (3 weeks ago), 2025-03-13 16:17:06 -0400
• Engine revision 18b71d647a
• Dart version 3.7.2
• DevTools version 2.42.3

[✓] Android toolchain - develop for Android devices (Android SDK version 35.0.0) [3.2s]
• Android SDK at /Users/da2ny/Library/Android/sdk
• Platform android-35, build-tools 35.0.0
• Java binary at: /Applications/Android Studio.app/Contents/jbr/Contents/Home/bin/java
This is the JDK bundled with the latest Android Studio installation on this machine.
To manually set the JDK path, use: `flutter config --jdk-dir="path/to/jdk"`.
• Java version OpenJDK Runtime Environment (build 21.0.5+-12932927-b750.29)
• All Android licenses accepted.

[✓] Xcode - develop for iOS and macOS (Xcode 16.2) [3.3s]
• Xcode at /Applications/Xcode.app/Contents/Developer
• Build 16C5032a
• CocoaPods version 1.16.2

[✓] Chrome - develop for the web [10ms]
• Chrome at /Applications/Google Chrome.app/Contents/MacOS/Google Chrome

[✓] Android Studio (version 2024.3) [10ms]
• 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
• Java version OpenJDK Runtime Environment (build 21.0.5+-12932927-b750.29)

[✓] VS Code (version 1.98.2) [9ms]
• VS Code at /Applications/Visual Studio Code.app/Contents
• Flutter extension version 3.106.0

[✓] Connected device (5 available) [13.2s]
• Core M5 (mobile) • ec4ad0bb • android-arm64 • Android 12 (API 31)
• macOS (desktop) • macos • darwin-arm64 • macOS 15.3.1 24D70 darwin-arm64
• Mac Designed for iPad (desktop) • mac-designed-for-ipad • darwin • macOS 15.3.1 24D70 darwin-arm64
• Chrome (web) • chrome • web-javascript • Google Chrome 134.0.6998.166

[✓] Network resources [299ms]
• All expected network resources are available.

• No issues found!
Process finished with exit code 0
```

Reproduce the issue with the shown ChewieController configuration, then trace the CupertinoControls progress bar and +10/-10 button seeking paths. Confirm the fix by verifying that seeking during playback does not leave the loading indicator visible indefinitely.

Written by the indexing model from the issue text.