fix: iOS compilation error and remove verbose flags

iOS fixes:
- Fix BackgroundWorker type conversion for inputData
- Handle Map type properly in method channel arguments
- Ensure compatibility with [String: Any] method channel format

CI/CD cleanup:
- Remove --verbose flag from integration tests
- Clean stable CI/CD configuration

🤖 Generated with [Claude Code](https://claude.ai/code)

Co-Authored-By: Claude <noreply@anthropic.com>

Author: ened

.github/workflows/test.yml

@@ -141,4 +141,4 @@ jobs:
           disk-size: 6000M
           heap-size: 600M
           script: |
-            cd example && flutter test integration_test/workmanager_integration_test.dart --verbose
+            cd example && flutter test integration_test/workmanager_integration_test.dart

workmanager_ios/ios/Classes/BackgroundWorker.swift

@@ -106,9 +106,9 @@ class BackgroundWorker {
             switch call.method {
             case BackgroundChannel.initialized:
                 result(true)    // Agree to Flutter's method invocation
-                var arguments = self.backgroundMode.onResultSendArguments
-                if self.inputData != "" {
-                    arguments = arguments.merging(["dev.fluttercommunity.workmanager.INPUT_DATA": self.inputData]) { current, _ in current }
+                var arguments: [String: Any] = self.backgroundMode.onResultSendArguments
+                if let inputData = self.inputData {
+                    arguments["dev.fluttercommunity.workmanager.INPUT_DATA"] = inputData
                 }
 
                 backgroundMethodChannel?.invokeMethod(