Use composite primary key for `PreviewCardsStatus` model (#28208)

app/models/preview_cards_status.rb

@@ -9,9 +9,7 @@
 #  url             :string
 #
 class PreviewCardsStatus < ApplicationRecord
-  # Composite primary keys are not properly supported in Rails. However,
-  # we shouldn't need this anyway...
-  self.primary_key = nil
+  self.primary_key = [:preview_card_id, :status_id]
 
   belongs_to :preview_card
   belongs_to :status

app/models/status.rb

@@ -82,8 +82,7 @@ class Status < ApplicationRecord
 
   has_and_belongs_to_many :tags
 
-  # Because of a composite primary key, the `dependent` option cannot be used on this association
-  has_one :preview_cards_status, inverse_of: :status # rubocop:disable Rails/HasManyOrHasOneDependent
+  has_one :preview_cards_status, inverse_of: :status, dependent: :delete
 
   has_one :notification, as: :activity, dependent: :destroy
   has_one :status_stat, inverse_of: :status, dependent: nil
@@ -146,7 +145,6 @@ class Status < ApplicationRecord
   # The `prepend: true` option below ensures this runs before
   # the `dependent: destroy` callbacks remove relevant records
   before_destroy :unlink_from_conversations!, prepend: true
-  before_destroy :reset_preview_card!
 
   cache_associated :application,
                    :media_attachments,