Add google/auth and related libraries, and update other dependencies

common/vendor/guzzlehttp/promises/src/PromisorInterface.php

@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace GuzzleHttp\Promise;
 
 /**
@@ -9,8 +11,6 @@ interface PromisorInterface
 {
     /**
      * Returns a promise.
-     *
-     * @return PromiseInterface
      */
-    public function promise();
+    public function promise(): PromiseInterface;
 }