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/PodcastModel.php

@@ -176,7 +176,7 @@ class PodcastModel extends Model
                     '`' . $prefix . 'fediverse_posts`.`published_at` <= UTC_TIMESTAMP()',
                     null,
                     false,
-                )->orWhere('fediverse_posts.published_at', null)
+                )->orWhere('fediverse_posts.published_at')
                 ->groupEnd()
                 ->groupBy('podcasts.actor_id')
                 ->orderBy('max_published_at', 'DESC');