Do not execute the job with the same arguments as the retry job (#4814)

lib/mastodon/unique_retry_job_middleware.rb

@@ -0,0 +1,20 @@
+# frozen_string_literal: true
+
+class Mastodon::UniqueRetryJobMiddleware
+  def call(_worker_class, item, _queue, _redis_pool)
+    return if item['unique_retry'] && retried?(item)
+    yield
+  end
+
+  private
+
+  def retried?(item)
+    # Use unique digest key of SidekiqUniqueJobs
+    unique_key = SidekiqUniqueJobs::UNIQUE_DIGEST_KEY
+    unique_digest = item[unique_key]
+    class_name = item['class']
+    retries = Sidekiq::RetrySet.new
+
+    retries.any? { |job| job.item['class'] == class_name && job.item[unique_key] == unique_digest }
+  end
+end