[Enhancement] Auto-update yt-dlp (#589)

* Added a command for updating yt-dlp

* Added a yt-dlp update worker to run daily

* Added a new file that runs post-boot when the app is ready to serve requests; put yt-dlp updater in there

* Updated config to expose the current env globally; updated startup tasks to not run in test env

* Removes unneeded test code

lib/pinchflat_web/endpoint.ex

@@ -20,7 +20,7 @@ defmodule PinchflatWeb.Endpoint do
   plug Plug.Static,
     at: "/",
     from: :pinchflat,
-    gzip: Mix.env() == :prod,
+    gzip: Application.compile_env(:pinchflat, :env) == :prod,
     only: PinchflatWeb.static_paths()
 
   # Code reloading can be explicitly enabled under the