Fix A11y tests (#5104)

* replace NavigationStack with ElementNavigationStack to allow the content to be rendered without a NavigationStack in a11y tests

* fix a11y tests

* update xcodeproject

* swiftformat fix

* use iOS 26.1 for CI

* use a wrapper to solve the issue for a11y tests

* ElementNavigationStack only uses the trick in DEBUG mode, and added a swiftlint rule to prevent the usage of NavigationStack

ElementX/Sources/Screens/JoinRoomScreen/View/JoinRoomScreen.swift

@@ -485,7 +485,7 @@ struct JoinRoomScreenPreviewWrapper: Identifiable {
         let previewDisplayName = customPreviewName ?? previewDisplayName
         let previewDisplayNameSuffix = isSpace ? " Space" : ""
         if mode == .forbidden {
-            NavigationStack {
+            ElementNavigationStack {
                 JoinRoomScreen(context: viewModel.context)
             }
             .snapshotPreferences(expect: viewModel.context.$viewState.map { state in
@@ -496,7 +496,7 @@ struct JoinRoomScreenPreviewWrapper: Identifiable {
             }
             .previewDisplayName(previewDisplayName + previewDisplayNameSuffix)
         } else {
-            NavigationStack {
+            ElementNavigationStack {
                 JoinRoomScreen(context: viewModel.context)
             }
             .snapshotPreferences(expect: viewModel.context.$viewState.map { state in