TextEditor: (Re-)Add virtual ICodeStylePreferencesFactory destructor

Got lost in e0c76647.

Change-Id: I56632199ee6904dd3830d123d1e30f9e950d11f6
Reviewed-by: Eike Ziller <eike.ziller@qt.io>

src/plugins/texteditor/icodestylepreferencesfactory.h

@@ -53,6 +53,7 @@ class TEXTEDITOR_EXPORT ICodeStylePreferencesFactory
 
 public:
     ICodeStylePreferencesFactory();
+    virtual ~ICodeStylePreferencesFactory() = default;
 
     virtual CodeStyleEditorWidget *createCodeStyleEditor(ICodeStylePreferences *codeStyle,
                                                          QWidget *parent = nullptr);