refactor: add closure void return type in tests (#1180)

Author: spiralbot

tests/PipelineTest.php

@@ -107,7 +107,7 @@ public function process(
 
         $this->container->runScope(
             new \Spiral\Core\Scope(name: 'http'),
-            function (ScopeInterface $c) use ($middleware) {
+            function (ScopeInterface $c) use ($middleware): void {
                 $request = new ServerRequest('GET', '');
                 $handler = new CallableHandler(fn() => 'response', new ResponseFactory(new HttpConfig(['headers' => []])));