feat(elasticsearch): introduce v7 support

Author: darthf1

src/Symfony/Bundle/DependencyInjection/Compiler/ElasticsearchClientPass.php

@@ -40,8 +40,10 @@ public function process(ContainerBuilder $container): void
         }
 
         if (class_exists(\Elasticsearch\ClientBuilder::class)) {
+            // ES v7
             $builderName = \Elasticsearch\ClientBuilder::class;
         } else {
+            // ES v8 and up
             $builderName = \Elastic\Elasticsearch\ClientBuilder::class;
         }