Remove leftover Gun connection pool test

test/pleroma/gun/connection_pool_test.exs

-# Pleroma: A lightweight social networking server
-# Copyright © 2017-2022 Pleroma Authors <https://pleroma.social/>
-# SPDX-License-Identifier: AGPL-3.0-only
-
-defmodule Pleroma.Gun.ConnectionPoolTest do
-  use Pleroma.DataCase
-
-  import Mox
-  import ExUnit.CaptureLog
-  alias Pleroma.Gun.ConnectionPool
-
-  defp gun_mock(_) do
-    Pleroma.GunMock
-    |> stub(:open, fn _, _, _ -> Task.start_link(fn -> Process.sleep(100) end) end)
-    |> stub(:await_up, fn _, _ -> {:ok, :http} end)
-    |> stub(:set_owner, fn _, _ -> :ok end)
-
-    :ok
-  end
-
-  setup :gun_mock
-
-  test "gives the same connection to 2 concurrent requests" do
-    Enum.map(
-      [
-        "http://www.korean-books.com.kp/KBMbooks/en/periodic/pictorial/20200530163914.pdf",
-        "http://www.korean-books.com.kp/KBMbooks/en/periodic/pictorial/20200528183427.pdf"
-      ],
-      fn uri ->
-        uri = URI.parse(uri)
-        task_parent = self()
-
-        Task.start_link(fn ->
-          {:ok, conn} = ConnectionPool.get_conn(uri, [])
-          ConnectionPool.release_conn(conn)
-          send(task_parent, conn)
-        end)
-      end
-    )
-
-    [pid, pid] =
-      for _ <- 1..2 do
-        receive do
-          pid -> pid
-        end
-      end
-  end
-
-  @tag :erratic
-  test "connection limit is respected with concurrent requests" do
-    clear_config([:connections_pool, :max_connections]) do
-      clear_config([:connections_pool, :max_connections], 1)
-      # The supervisor needs a reboot to apply the new config setting
-      Process.exit(Process.whereis(Pleroma.Gun.ConnectionPool.WorkerSupervisor), :kill)
-
-      on_exit(fn ->
-        Process.exit(Process.whereis(Pleroma.Gun.ConnectionPool.WorkerSupervisor), :kill)
-      end)
-    end
-
-    capture_log(fn ->
-      Enum.map(
-        [
-          "https://ninenines.eu/",
-          "https://youtu.be/PFGwMiDJKNY"
-        ],
-        fn uri ->
-          uri = URI.parse(uri)
-          task_parent = self()
-
-          Task.start_link(fn ->
-            result = ConnectionPool.get_conn(uri, [])
-            # Sleep so that we don't end up with a situation,
-            # where request from the second process gets processed
-            # only after the first process already released the connection
-            Process.sleep(50)
-
-            case result do
-              {:ok, pid} ->
-                ConnectionPool.release_conn(pid)
-
-              _ ->
-                nil
-            end
-
-            send(task_parent, result)
-          end)
-        end
-      )
-
-      [{:error, :pool_full}, {:ok, _pid}] =
-        for _ <- 1..2 do
-          receive do
-            result -> result
-          end
-        end
-        |> Enum.sort()
-    end)
-  end
-end