Cancel remote fetch jobs for deleted objects

lib/pleroma/workers/remote_fetcher_worker.ex

@@ -18,6 +18,9 @@ def perform(%Job{args: %{"op" => "fetch_remote", "id" => id} = args}) do
       {:error, reason = "Object fetch has been denied"} ->
         {:cancel, reason}
 
+      {:error, reason = "Object has been deleted"} ->
+        {:cancel, reason}
+
       _ ->
         :error
     end