tests: update qPrefAnimations test cases

remove include of QtTest in header, becaue it is not needed,
add include of QObject in header, so moc can generate code.
add QTest in cpp file, which replaces QtTest

Signed-off-by: Jan Iversen <jani@apache.org>

tests/testqPrefAnimations.cpp

@@ -1,11 +1,12 @@
 // SPDX-License-Identifier: GPL-2.0
 #include "testqPrefAnimations.h"
 
-#include "core/settings/qPrefAnimations.h"
+#include "core/settings/qPref.h"
 #include "core/pref.h"
 #include "core/qthelper.h"
 
 #include <QDate>
+#include <QTest>
 
 void TestQPrefAnimations::initTestCase()
 {

tests/testqPrefAnimations.h

@@ -2,7 +2,7 @@
 #ifndef TESTQPREFANIMATIONS_H
 #define TESTQPREFANIMATIONS_H
 
-#include <QtTest>
+#include <QObject>
 
 class TestQPrefAnimations : public QObject
 {