tst_QTextEdit::inputMethodEvent() remove setActiveWindow()

2f6fe3a268 as made calls to
QApplicationPrivate::setActiveWindow() redundant.

Remove redundant calls.

Task-number: QTBUG-121488
Change-Id: I53e5f5c58a7a404c1886edb5c076250388e47ab9
Reviewed-by: Axel Spoerl <axel.spoerl@qt.io>

tests/auto/widgets/widgets/qtextedit/tst_qtextedit.cpp

@@ -2545,7 +2545,6 @@ void tst_QTextEdit::inputMethodEvent()
 
     // test that input method gets chance to commit preedit when removing focus
     ed->setText("");
-    QApplicationPrivate::setActiveWindow(ed);
     QTRY_VERIFY(QApplication::focusWindow());
     QCOMPARE(qApp->focusObject(), ed);