graphqlservice target no longer works without graphqlintrospection

[wravery]

Even schemas generated with schemagen --no-introspection need to reference all of the symbols in graphqlintrospection in GetSchema():

std::shared_ptr<schema::Schema> GetSchema()
{
	static std::weak_ptr<schema::Schema> s_wpSchema;
	auto schema = s_wpSchema.lock();

	if (!schema)
	{
		schema = std::make_shared<schema::Schema>(true, R"md()md"sv);
		introspection::AddTypesToSchema(schema);
		AddTypesToSchema(schema);
		s_wpSchema = schema;
	}

	return schema;
}