chore: fix phpDoc for return values

Author: Chris8934

src/Plugin/CookiePlugin.php

@@ -164,7 +164,7 @@ private function createCookie(RequestInterface $request, string $setCookieHeader
      *
      * @param string $part A single cookie value in format key=value
      *
-     * @return array{0:string, 1:?string}
+     * @return array{0:string, 1?:string}
      */
     private function createValueKey(string $part): array
     {

src/Plugin/RedirectPlugin.php

@@ -113,7 +113,7 @@ final class RedirectPlugin implements Plugin
     private $streamFactory;
 
     /**
-     * @param array{'preserve_header'?: bool|string[], 'use_default_for_multiple'?: bool, 'strict'?: bool} $config
+     * @param array{'preserve_header'?: bool|string[], 'use_default_for_multiple'?: bool, 'strict'?: bool, 'stream_factory'?:StreamFactoryInterface} $config
      *
      * Configuration options:
      *   - preserve_header: True keeps all headers, false remove all of them, an array is interpreted as a list of header names to keep