Remove redundant ob_flush() call in SseTransport

The ob_flush() call was unnecessary as flush() suffices for ensuring the output is sent to the client. Removing it simplifies the code while maintaining its intended functionality.

Author: klapaudius

src/Transports/SseTransport.php

@@ -110,7 +110,6 @@ private function sendEvent(string $event, string $data): void
         $this->logger?->debug('SSE Transport::sendEvent: event: '.$event.PHP_EOL.'data: '.$data.PHP_EOL);
 
         // Just ensure output gets flushed
-        ob_flush(); // Flushes the active buffer
         flush(); // Flushes the system-level buffer (important for real-time outputs)
 
         echo sprintf('event: %s', $event).PHP_EOL;