Moving some background jobs into simple tasks

- fetching activity data
- attachment prefetching
- using limiter to prevent overload

lib/pleroma/workers/background_worker.ex

@@ -3,9 +3,7 @@
 # SPDX-License-Identifier: AGPL-3.0-only
 
 defmodule Pleroma.Workers.BackgroundWorker do
-  alias Pleroma.Activity
   alias Pleroma.User
-  alias Pleroma.Web.ActivityPub.MRF.MediaProxyWarmingPolicy
 
   use Pleroma.Workers.WorkerHelper, queue: "background"
 
@@ -32,19 +30,6 @@ defmodule Pleroma.Workers.BackgroundWorker do
     {:ok, User.Import.perform(String.to_atom(op), user, identifiers)}
   end
 
-  def perform(%Job{args: %{"op" => "media_proxy_preload", "message" => message}}) do
-    MediaProxyWarmingPolicy.perform(:preload, message)
-  end
-
-  def perform(%Job{args: %{"op" => "media_proxy_prefetch", "url" => url}}) do
-    MediaProxyWarmingPolicy.perform(:prefetch, url)
-  end
-
-  def perform(%Job{args: %{"op" => "fetch_data_for_activity", "activity_id" => activity_id}}) do
-    activity = Activity.get_by_id(activity_id)
-    Pleroma.Web.RichMedia.Helpers.perform(:fetch, activity)
-  end
-
   def perform(%Job{
         args: %{"op" => "move_following", "origin_id" => origin_id, "target_id" => target_id}
       }) do