frankenphp: don't stop the worker script even if a connection with a client is aborted (#155)

See php/frankenphp#316 and
php/frankenphp#310 (comment).

Author: dunglas

src/frankenphp-symfony/src/Runner.php

@@ -22,6 +22,9 @@ public function __construct(private HttpKernelInterface $kernel)
 
     public function run(): int
     {
+        // Prevent worker script termination when a client connection is interrupted
+        ignore_user_abort(true);
+
         $server = array_filter($_SERVER, static fn (string $key) => !str_starts_with($key, 'HTTP_'), ARRAY_FILTER_USE_KEY);
         $server['APP_RUNTIME_MODE'] = 'web=1&worker=1';