feat(docker): replace all-in-one image with FrankenPHP and Caddy based image + discard other images

- use serversideup/php as a base image
- remove nginx unit base
- remove app / webserver images
- add bundle stage to remove pipeline dependency
- update docker setup docs
- edit gitlabci rules and release logic

modules/Admin/Controllers/NotificationController.php

@@ -75,7 +75,7 @@ class NotificationController extends BaseController
     {
         $notifications = new NotificationModel()
             ->where('target_actor_id', $podcast->actor_id)
-            ->where('read_at', null)
+            ->where('read_at')
             ->findAll();
 
         foreach ($notifications as $notification) {