Disconnect `EditorNode` from file dialogs on destruction

editor/editor_node.cpp

@@ -8076,6 +8076,17 @@ EditorNode::~EditorNode() {
 	GDExtensionEditorPlugins::editor_node_add_plugin = nullptr;
 	GDExtensionEditorPlugins::editor_node_remove_plugin = nullptr;
 
+	FileDialog::get_icon_func = nullptr;
+	FileDialog::register_func = nullptr;
+	FileDialog::unregister_func = nullptr;
+
+	EditorFileDialog::get_icon_func = nullptr;
+	EditorFileDialog::register_func = nullptr;
+	EditorFileDialog::unregister_func = nullptr;
+
+	file_dialogs.clear();
+	editor_file_dialogs.clear();
+
 	singleton = nullptr;
 }