fix: correct UniTask.WhenAny return type handling in UwbWebView

Windows build was failing with:
error CS0019: Operator '==' cannot be applied to operands of type 'bool' and 'int'

ROOT CAUSE:
UniTask.WhenAny has different return types depending on input types:
- WhenAny(UniTask<T>, UniTask<U>) returns (int, T/U) tuple
- WhenAny(UniTask<T>, UniTask) returns int index directly

Our case: WhenAny(UniTask<bool>, UniTask.Delay(...))
- UniTask.Delay returns UniTask (void), not UniTask<T>
- So WhenAny returns int, not tuple

FIX:
Changed from: var (winIndex, _) = await UniTask.WhenAny(...)
Changed to:   int winIndex = await UniTask.WhenAny(...)

Author: rodrigo-fournier-immutable

src/Packages/Passport/Runtime/Scripts/Private/Uwb/UwbWebView.cs

@@ -138,7 +138,8 @@ private async UniTask WaitForClientConnected(WebBrowserClient webBrowserClient)
             Debug.Log($"[UwbWebView] Waiting up to {timeoutSeconds} seconds for OnLoadFinish event...");
 
             // Race between completion and timeout
-            var (winIndex, _) = await UniTask.WhenAny(completionTask, timeoutTask);
+            // WhenAny with UniTask<T> and UniTask (void) returns int index directly
+            int winIndex = await UniTask.WhenAny(completionTask, timeoutTask);
 
             if (winIndex == 1) // Timeout won
             {