[webview_flutter_wkwebview] Tear down ProxyAPIRegistrar in applicationWillTerminate

[bparrishMines]

Relands #11484

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[gemini-code-assist]

Code Review

This pull request updates the webview_flutter_wkwebview plugin to version 3.24.6, increases the minimum supported SDK versions to Flutter 3.38 and Dart 3.10, and implements logic to tear down the ProxyAPIRegistrar when the application terminates or a scene disconnects on iOS. Review feedback notes that PlatformViewImplTests.swift is referenced in the project file but missing from the PR, warns that sceneDidDisconnect might prematurely destroy state in multi-scene applications, suggests safer handling of optional scenes in tests, and identifies redundant setup calls in the new test file.

[gemini-code-assist]

The project file has been updated to include PlatformViewImplTests.swift, but this file is missing from the pull request patches. This will result in a build error in Xcode due to a missing file reference. Please ensure all new test files are included in the commit.

[gemini-code-assist]

Tearing down the ProxyAPIRegistrar in sceneDidDisconnect may be problematic for applications that support multiple scenes (e.g., on iPad). If one scene is disconnected while others remain active and share the same Flutter engine, the plugin's state will be destroyed for all scenes, potentially breaking the remaining webviews. Since applicationWillTerminate and detachFromEngine already handle cleanup for the app and engine respectively, consider if sceneDidDisconnect is necessary or if it should be removed to avoid side effects in multi-window scenarios.

[gemini-code-assist]

Using a forced unwrap on UIApplication.shared.connectedScenes.first can lead to a crash during test execution if the test environment does not have any active scenes. It is safer to use a guard statement or an optional binding to handle cases where no scenes are connected.

Suggested change

	let scene = UIApplication.shared.connectedScenes.first!
	guard let scene = UIApplication.shared.connectedScenes.first else {
	XCTFail("No connected scenes found.")
	return
	}

[gemini-code-assist]

The call to plugin.proxyApiRegistrar!.setUp() is redundant because the WebViewFlutterPlugin initializer already calls setUp() on the registrar. This can be removed to avoid unnecessary re-initialization of the ProxyAPI.

[gemini-code-assist]

The call to plugin.proxyApiRegistrar!.setUp() is redundant here as well, as the plugin's initializer already handles the setup of the registrar.

[stuartmorgan-g]

Weren't these added in 3.41, not 3.38?