Mark services private

graphql_fragment_include.services.yml

 services:
   graphql_fragment_include.graphql_fragment_loader:
+    public: false
     class: Drupal\graphql_fragment_include\GraphQL\Fragment\GraphQLFragmentLoader
     arguments:
       - "@config.factory"
       - "@logger.factory"
 
   graphql.query_processor:
+    public: false
     class: Drupal\graphql_fragment_include\GraphQL\Execution\QueryProcessor
     arguments:
       - '@cache_contexts_manager'