fix: crash from appcenter in rare scenario

Stack trace:

closure #1 () -> () in AltTab.(windowDestroyed in _3E1A2D100A6A10BAACF80B17AC9C41B5)(__C.AXUIElementRef) throws -> () Windows.swift:43
reabstraction thunk helper from @escaping @callee_guaranteed () -> () to @escaping @callee_unowned @convention(block) () -> () <compiler-generated>:0

src/logic/Windows.swift

@@ -94,10 +94,10 @@ class Windows {
         return targetIndex
     }
 
-    static func moveFocusedWindowIndexAfterWindowDestroyedInBackground(_ destroyedWindowIndex: Int) {
-        if focusedWindowIndex > destroyedWindowIndex {
+    static func moveFocusedWindowIndexAfterWindowDestroyedInBackground(_ window: Window) {
+        if focusedWindowIndex > window.lastFocusOrder {
             cycleFocusedWindowIndex(-1)
-        } else if focusedWindowIndex == destroyedWindowIndex && !focusedWindow()!.shouldShowTheUser {
+        } else if focusedWindowIndex == window.lastFocusOrder && !window.shouldShowTheUser {
             cycleFocusedWindowIndex(1)
         }
     }

src/logic/events/AccessibilityEvents.swift

@@ -151,7 +151,7 @@ private func windowDestroyed(_ element: AXUIElement) throws {
             Windows.removeAndUpdateFocus(window)
             let windowlessApp = window.application.addWindowslessAppsIfNeeded()
             if Windows.list.count > 0 {
-                Windows.moveFocusedWindowIndexAfterWindowDestroyedInBackground(window.lastFocusOrder)
+                Windows.moveFocusedWindowIndexAfterWindowDestroyedInBackground(window)
                 App.app.refreshOpenUi(windowlessApp)
             } else {
                 App.app.hideUi()