refactor: Use override instead of virtual where possible (#4917)

src/widgets/AttachedWindow.hpp

@@ -28,7 +28,7 @@ public:
         bool fullscreen = false;
     };
 
-    virtual ~AttachedWindow() override;
+    ~AttachedWindow() override;
 
     static AttachedWindow *get(void *target_, const GetArgs &args);
 #ifdef USEWINSDK
@@ -39,7 +39,7 @@ public:
     void setChannel(ChannelPtr channel);
 
 protected:
-    virtual void showEvent(QShowEvent *) override;
+    void showEvent(QShowEvent *) override;
     //    virtual void nativeEvent(const QByteArray &eventType, void *message,
     //    long *result) override;