fix: detect https scheme from transport param in Connection::getClient()

The ES9 PHP SDK client in getClient() was only checking the 'ssl' param
to determine the HTTP scheme. However, ECS environments configure clusters
with 'transport: https' (without 'ssl: true'), causing HTTP requests to
be sent to HTTPS endpoints (nginx returns 400).

Now also checks strtolower(getTransport()) === 'https' so that clusters
with transport: https get the correct https:// scheme in the SDK client URL.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

Author: sumitkhopade1986

src/Connection.php

@@ -293,7 +293,8 @@ public function getClient(): ElasticsearchClient
         }
 
         $hosts = [];
-        $scheme = $this->hasParam('ssl') && $this->getParam('ssl') ? 'https' : 'http';
+        $scheme = ($this->hasParam('ssl') && $this->getParam('ssl'))
+            || \strtolower((string)$this->getTransport()) === 'https' ? 'https' : 'http';
         $host = $this->getHost();
         $port = $this->getPort();
         $path = $this->getPath();