QFactoryLoader: unconditionally provide toJson

Amends c0a8cfe167. The StaticPluginLoader
needs it, too, and that one is available in non-library configurations.

Change-Id: I5d396e78abe7358a5df5ef816cfe92137d3ae4b5
Reviewed-by: Alexey Edelev <alexey.edelev@qt.io>
Reviewed-by: Andrei Golubev <andrei.golubev@qt.io>
Reviewed-by: Qt CI Bot <qt_ci_bot@qt-project.org>
Reviewed-by: Thiago Macieira <thiago.macieira@intel.com>

src/corelib/plugin/qfactoryloader.cpp

@@ -105,7 +105,6 @@ bool QPluginParsedMetaData::parse(QByteArrayView raw)
     return true;
 }
 
-#if QT_CONFIG(library)
 QJsonObject QPluginParsedMetaData::toJson() const
 {
     // convert from the internal CBOR representation to an external JSON one
@@ -127,7 +126,6 @@ QJsonObject QPluginParsedMetaData::toJson() const
     }
     return o;
 }
-#endif
 
 class QFactoryLoaderPrivate : public QObjectPrivate
 {