Port from qAsConst() to std::as_const()

We've been requiring C++17 since Qt 6.0, and our qAsConst use finally
starts to bother us (QTBUG-99313), so time to port away from it
now.

Since qAsConst has exactly the same semantics as std::as_const (down
to rvalue treatment, constexpr'ness and noexcept'ness), there's really
nothing more to it than a global search-and-replace.

Task-number: QTBUG-99313
Change-Id: I88edd91395849574436299b8badda21bb93bea39
Reviewed-by: hjk <hjk@qt.io>

src/plugins/macros/macro.cpp

@@ -121,7 +121,7 @@ bool Macro::save(const QString &fileName, QWidget *parent)
         QDataStream stream(saver.file());
         stream << d->version;
         stream << d->description;
-        for (const MacroEvent &event : qAsConst(d->events)) {
+        for (const MacroEvent &event : std::as_const(d->events)) {
             event.save(stream);
         }
         saver.setResult(&stream);