Destroy EditorFilesystem/EditorSettings on test shutdown

Otherwise asan complains if a test tries to use these.

Split off from https://github.com/godotengine/godot/pull/98909

editor/editor_file_system.cpp

@@ -3556,5 +3556,9 @@ EditorFileSystem::EditorFileSystem() {
 }
 
 EditorFileSystem::~EditorFileSystem() {
+	if (filesystem) {
+		memdelete(filesystem);
+	}
+	filesystem = nullptr;
 	ResourceSaver::set_get_resource_id_for_path(nullptr);
 }