Fix PCH file for Qt6

Change-Id: I273af019758d56bca159e517a45b68f8d3a16f5e
Reviewed-by: Cristian Adam <cristian.adam@qt.io>

src/shared/qtcreator_pch.h

@@ -62,7 +62,6 @@
 #include <QRegularExpression>
 #include <QString>
 #include <QStringList>
-#include <QTextCodec>
 #include <QPointer>
 #include <QScopedPointer>
 #include <QSharedPointer>
@@ -77,6 +76,8 @@ using Qt::dec;
 using Qt::showbase;
 using Qt::hex;
 using Qt::noforcesign;
+#else
+#include <QTextCodec>
 #endif
 
 #include <stdlib.h>