qtversionchecks.h: hide Q_OBJECT macro in C-style comment from automoc

Due to https://gitlab.kitware.com/cmake/cmake/-/issues/25770, the
presence of the Q_OBJECT macro here triggers automoc rule generation,
followed by moc's "No relevant classes found. No output generated."
warning.

Comment the macro out until the issue is fixed, leaving a comment to
avoid a helpful soul commenting the macro back in again.

Amends 32a1151245.

Task-number: QTBUG-123229
Pick-to: 6.7
Change-Id: I5387128f8fcd2793f0d4b9ff73a551999fea84b0
Reviewed-by: Joerg Bornemann <joerg.bornemann@qt.io>
Reviewed-by: Ahmad Samir <a.samirh78@gmail.com>

src/corelib/global/qtversionchecks.h

@@ -95,7 +95,7 @@
     To mark parts of a class:
         class QClass : public QObject
         {
-            Q_OBJECT
+            // Q_OBJECT omitted d/t QTBUG-123229
 
             QT_TECH_PREVIEW_API
             Q_PROPERTY(int countNG ...)   // this is TP