robots txt test fix

test/tasks/robots_txt_test.exs

@@ -3,7 +3,7 @@
 # SPDX-License-Identifier: AGPL-3.0-only
 
 defmodule Mix.Tasks.Pleroma.RobotsTxtTest do
-  use ExUnit.Case, async: true
+  use ExUnit.Case
   alias Mix.Tasks.Pleroma.RobotsTxt
 
   test "creates new dir" do