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

app/Models/PostModel.php

@@ -50,7 +50,7 @@ class PostModel extends FediversePostModel
         return $this->where([
             'episode_id' => $episodeId,
         ])
-            ->where('in_reply_to_id', null)
+            ->where('in_reply_to_id')
             ->where('`published_at` <= UTC_TIMESTAMP()', null, false)
             ->orderBy('published_at', 'DESC')
             ->findAll();