Add network reachability plugin on macOS.

external/qt/qt6/CMakeLists.txt

@@ -159,6 +159,7 @@ else()
             lib/${qt_lib_prefix}Qt6BundledFreetype
             plugins/platforms/${qt_lib_prefix}qcocoa
             plugins/tls/${qt_lib_prefix}qsecuretransportbackend
+            plugins/networkinformation/${qt_lib_prefix}qscnetworkreachability
         )
         foreach (lib ${qt_libs})
             list(APPEND qt_libs_list "${qt_loc}/${lib}${qt_lib_suffix}")

external/qt/qt_static_plugins/qt_static_plugins.cpp

@@ -12,6 +12,7 @@ https://github.com/desktop-app/legal/blob/master/LEGAL
 
 #ifdef Q_OS_MAC
 Q_IMPORT_PLUGIN(QSecureTransportBackend)
+Q_IMPORT_PLUGIN(QSCNetworkReachabilityNetworkInformationBackendFactory)
 #else // Q_OS_MAC
 Q_IMPORT_PLUGIN(QTlsBackendOpenSSL)
 #endif // Q_OS_MAC