Fix formatting issues in sliding list partitioning

Follow-up from
https://gitlab.com/gitlab-org/gitlab/-/merge_requests/73406

lib/gitlab/database/partitioning/partition_manager.rb

@@ -73,6 +73,7 @@ module Gitlab
                                        partition_name: partition.partition_name,
                                        table_name: partition.table)
               end
+
               model.partitioning_strategy.after_adding_partitions
             end
           end