Get.defaultTransition cannot be null, customize PageTransitionsTheme does not take effect.

[boomcx]

Describe the bug
When Get.root launch, Get.context is null, and Get.theme always returns ThemeData.fallback(), so config.defaultTransition always has a value， it's impossible to be null.

Screenshots

example:

void main() => runApp(MaterialApp(home: MyApp()));

class MyApp extends StatelessWidget {
  const MyApp({super.key});

  @override
  Widget build(BuildContext context) {
    return GetMaterialApp.router(
      debugShowCheckedModeBanner: false,
      getPages: AppPages.routes,
      backButtonDispatcher: MRootBackButtonDispatcher(),
      theme: ThemeData(
        pageTransitionsTheme: const PageTransitionsTheme(
          builders: {
            // TargetPlatform.android: PopScopePageTransitionsBuilder(),
            TargetPlatform.iOS: PopScopePageTransitionsBuilder(),
          },
        ),
      ), 
    );
  }
}

Expected behavior

I think replacing

Get.theme.pageTransitionsTheme.builders[platform]

with

(config.theme ?? Get.theme).pageTransitionsTheme.builders[platform]

in the GetRootState.getThemeTransition method，can solve this problem.

Flutter Version:

Flutter 3.24.5 • channel stable • https://github.com/flutter/flutter.git
Framework • revision dec2ee5c1f (5 weeks ago) • 2024-11-13 11:13:06 -0800
Engine • revision a18df97ca5
Tools • Dart 3.5.4 • DevTools 2.37.3

Getx Version:

get: ^5.0.0-release-candidate-9.2.1

Describe on which device you found the bug:

iPhone12