[Housekeeping] Improve test stability (#232)

* Ensured all tests use at least the DataCase module

* addressed one flakey test

* More flakey tests

* Consolidated Mox usage

test/pinchflat/media_test.exs

@@ -1,7 +1,6 @@
 defmodule Pinchflat.MediaTest do
   use Pinchflat.DataCase
 
-  import Mox
   import Pinchflat.TasksFixtures
   import Pinchflat.MediaFixtures
   import Pinchflat.ProfilesFixtures
@@ -13,8 +12,6 @@ defmodule Pinchflat.MediaTest do
 
   alias Pinchflat.YtDlp.Media, as: YtDlpMedia
 
-  setup :verify_on_exit!
-
   @invalid_attrs %{title: nil, media_id: nil, media_filepath: nil}
 
   describe "schema" do