Remove the backup gem from Mastodon

The shared backup cookbook hardcodes postgresql-client-12, which does not exist on Ubuntu 24.04. Drop the Mastodon backup recipe and its role inclusion; the PostgreSQL standby is the safety net. The backup cookbook itself is still used by other services.

roles/mastodon.rb

@@ -8,5 +8,4 @@ run_list %w(
   role[postgresql_client]
   kosmos-mastodon::libretranslate
   kosmos-mastodon
-  kosmos-mastodon::backup
 )

site-cookbooks/kosmos-mastodon/metadata.rb

@@ -6,7 +6,6 @@ description      'Installs/Configures Mastodon'
 long_description IO.read(File.join(File.dirname(__FILE__), 'README.md'))
 version          '0.2.1'
 
-depends 'backup'
 depends 'elasticsearch'
 depends 'firewall'
 depends 'postgresql'

site-cookbooks/kosmos-mastodon/recipes/backup.rb

@@ -1,17 +0,0 @@
-#
-# Cookbook Name:: kosmos-mastodon
-# Recipe:: backup
-#
-
-postgresql_data_bag_item = data_bag_item('credentials', 'postgresql')
-
-unless node.chef_environment == "development"
-  node.override['backup']['s3']['keep'] = 1
-  node.override["backup"]["postgresql"]["host"] = "pg.kosmos.local"
-  node.override["backup"]["postgresql"]["databases"]["mastodon"] = {
-    username: "mastodon",
-    password: postgresql_data_bag_item['mastodon_user_password']
-  }
-
-  include_recipe "backup"
-end