Don't push to cache buster if attachment path is nil (#31414)

app/models/media_attachment.rb

@@ -422,7 +422,7 @@ class MediaAttachment < ApplicationRecord
       attachment = public_send(attachment_name)
       styles = DEFAULT_STYLES | attachment.styles.keys
       styles.map { |style| attachment.path(style) }
-    end
+    end.compact
   rescue => e
     # We really don't want any error here preventing media deletion
     Rails.logger.warn "Error #{e.class} busting cache: #{e.message}"

spec/models/media_attachment_spec.rb

@@ -302,12 +302,10 @@ RSpec.describe MediaAttachment, :attachment_processing do
     it 'queues CacheBusterWorker jobs' do
       original_path = media.file.path(:original)
       small_path = media.file.path(:small)
-      thumbnail_path = media.thumbnail.path(:original)
 
       expect { media.destroy }
         .to enqueue_sidekiq_job(CacheBusterWorker).with(original_path)
         .and enqueue_sidekiq_job(CacheBusterWorker).with(small_path)
-        .and enqueue_sidekiq_job(CacheBusterWorker).with(thumbnail_path)
     end
   end