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/ios/iosprobe.cpp

@@ -103,7 +103,7 @@ void XcodeProbe::setupDefaultToolchains(const QString &devPath)
     }
 
     if (!clangProfile.cCompilerPath.isEmpty() || !clangProfile.cxxCompilerPath.isEmpty()) {
-        for (const QString &arch : qAsConst(allArchitectures)) {
+        for (const QString &arch : std::as_const(allArchitectures)) {
             const QString clangFullName = QString(QLatin1String("Apple Clang (%1)")).arg(arch)
                     + ((devPath != defaultDeveloperPath)
                        ? QString(QLatin1String(" in %1")).arg(devPath)