chore: revert "update Authorization to not use Bearer id"

This reverts commit e8c2508.

src/HttpClient/Plugin/Authentication.php

@@ -43,7 +43,7 @@ private function getAuthorizationHeader(): string
     {
         switch ($this->method) {
             case Client::AUTH_ACCESS_TOKEN:
-                return $this->tokenOrLogin;
+                return sprintf('Bearer %s', $this->tokenOrLogin);
             default:
                 throw new RuntimeException(sprintf('%s not yet implemented', $this->method));
         }