Fix some qt6 compile errors

collectionlist.h

@@ -21,11 +21,12 @@
 #include <QVector>
 #include <QReadWriteLock>
 
+#include <KFileItem>
+
 #include "playlist.h"
 #include "playlistitem.h"
 
 class ViewMode;
-class KFileItem;
 class KFileItemList;
 class KDirWatch;
 

systemtray.cpp

@@ -88,7 +88,11 @@ void PassiveInfo::timerExpired()
         emit timeExpired();
 }
 
-void PassiveInfo::enterEvent(QEvent *)
+#if QT_VERSION >= QT_VERSION_CHECK(6, 0, 0)
+void PassiveInfo::enterEvent (QEnterEvent *)
+#else
+void PassiveInfo::enterEvent (QEvent *)
+#endif
 {
     m_startFadeTimer->stop();
     emit mouseEntered();

systemtray.h

@@ -63,9 +63,13 @@ signals:
     void nextSong();
 
 protected:
-    virtual void enterEvent(QEvent *) override;
-    virtual void leaveEvent(QEvent *) override;
-    virtual void wheelEvent(QWheelEvent *) override;
+#if QT_VERSION >= QT_VERSION_CHECK(6, 0, 0)
+    void enterEvent (QEnterEvent *e) override;
+#else
+    void enterEvent (QEvent *e) override;
+#endif
+    void leaveEvent(QEvent *) override;
+    void wheelEvent(QWheelEvent *) override;
 
 private:
     // Move us near the required position.