chore: bump native Swift SDK to 6.0.0 (#124)

Co-authored-by: Claude Opus 5.5 <noreply@anthropic.com>

Author: muzahidul-opti

.github/copilot-instructions.md

@@ -12,7 +12,7 @@ This is a **Flutter SDK** wrapping native Optimizely SDKs for iOS and Android.
 - **Dart/Flutter**: Cross-platform API layer (>=2.16.2, Flutter >=3.44.0)
 - **Swift**: iOS native bridge (Swift 5.0, iOS 15.0+)
 - **Kotlin/Java**: Android native bridge (Kotlin 2.1.0, Android 5.0+)
-- **Native SDKs**: OptimizelySwiftSDK 5.5.0 (iOS), android-sdk 5.4.0 (Android)
+- **Native SDKs**: OptimizelySwiftSDK 6.0.0 (iOS), android-sdk 5.4.0 (Android)
 
 ## Folder Structure
 

ios/optimizely_flutter_sdk/Package.swift

@@ -10,7 +10,7 @@ let package = Package(
     ],
     dependencies: [
         .package(name: "FlutterFramework", path: "../FlutterFramework"),
-        .package(url: "https://github.com/optimizely/swift-sdk.git", exact: "5.5.0")
+        .package(url: "https://github.com/optimizely/swift-sdk.git", exact: "6.0.0")
     ],
     targets: [
         .target(