Refactor the async user refreshing to use Oban

Previous implementation could cause duplicate simultaneous profile fetches which is not polite.

lib/pleroma/user.ex

@@ -38,6 +38,7 @@ defmodule Pleroma.User do
   alias Pleroma.Web.OAuth
   alias Pleroma.Web.RelMe
   alias Pleroma.Workers.BackgroundWorker
+  alias Pleroma.Workers.UserRefreshWorker
 
   require Logger
   require Pleroma.Constants
@@ -2165,12 +2166,9 @@ defmodule Pleroma.User do
   end
 
   defp maybe_refresh(user) do
-    fun = fn -> needs_update?(user) && fetch_by_ap_id(user.ap_id) end
-
-    if Config.get([__MODULE__, :sync_refreshing], false) do
-      fun.()
-    else
-      Task.start(fun)
+    if needs_update?(user) do
+      UserRefreshWorker.new(%{"ap_id" => user.ap_id})
+      |> Oban.insert()
     end
   end
 

lib/pleroma/workers/user_refresh_worker.ex

@@ -0,0 +1,14 @@
+# Pleroma: A lightweight social networking server
+# Copyright © 2017-2022 Pleroma Authors <https://pleroma.social/>
+# SPDX-License-Identifier: AGPL-3.0-only
+
+defmodule Pleroma.Workers.UserRefreshWorker do
+  use Pleroma.Workers.WorkerHelper, queue: "background", max_attempts: 1, unique: [period: 300]
+
+  alias Pleroma.User
+
+  @impl Oban.Worker
+  def perform(%Job{args: %{"ap_id" => ap_id}}) do
+    User.fetch_by_ap_id(ap_id)
+  end
+end