Fix bug in which teardowns can be called multiple times on the same coordinator

ElementX/Sources/Application/Navigation/NavigationCoordinators.swift

@@ -229,15 +229,13 @@ class NavigationSplitCoordinator: CoordinatorProtocol, ObservableObject, CustomS
     ///
     /// For added complexity, the NavigationSplitCoordinator has an internal compact layout NavigationStack for which we need to manually nil things again
     private func releaseAllCoordinatorReferences() {
-        sidebarModule?.tearDown()
-        detailModule?.tearDown()
-        sheetModule?.tearDown()
-        fullScreenCoverModule?.tearDown()
+        sidebarModule = nil
+        detailModule = nil
+        sheetModule = nil
+        fullScreenCoverModule = nil
         
-        compactLayoutRootModule?.tearDown()
-        compactLayoutStackModules.forEach { module in
-            module.tearDown()
-        }
+        compactLayoutRootModule = nil
+        compactLayoutStackModules.removeAll()
     }
     
     private func logPresentationChange(_ change: String, _ module: NavigationModule) {
@@ -626,13 +624,10 @@ class NavigationStackCoordinator: ObservableObject, CoordinatorProtocol, CustomS
     /// when a NavigationModule is dismissed. As the NavigationModule is just a wrapper multiple instances of it continuing living is of no consequence
     /// https://stackoverflow.com/questions/73885353/found-a-strange-behaviour-of-state-when-combined-to-the-new-navigation-stack/
     func stop() {
-        rootModule?.tearDown()
-        sheetModule?.tearDown()
-        fullScreenCoverModule?.tearDown()
-        
-        stackModules.forEach { module in
-            module.tearDown()
-        }
+        rootModule = nil
+        sheetModule = nil
+        fullScreenCoverModule = nil
+        stackModules.removeAll()
     }
     
     // MARK: - CustomStringConvertible