Fix mute screen layout on iPad

Closes #276

Tusker/Screens/Mute/MuteAccountView.swift

@@ -40,8 +40,15 @@ struct MuteAccountView: View {
     @State private var error: Error?
     
     var body: some View {
-        NavigationView {
-            navigationViewContent
+        if #available(iOS 16.0, *) {
+            NavigationStack {
+                navigationViewContent
+            }
+        } else {
+            NavigationView {
+                navigationViewContent
+            }
+            .navigationViewStyle(.stack)
         }
     }