Remove unused code

ee/app/workers/geo/prune_event_log_worker.rb

@@ -7,13 +7,10 @@ module Geo
     # This worker does not perform work scoped to a context
     include CronjobQueue
     # rubocop:enable Scalability/CronWorkerContext
-    include ::Gitlab::Utils::StrongMemoize
     include ::Gitlab::Geo::LogHelpers
 
     feature_category :geo_replication
 
-    LEASE_TIMEOUT = 5.minutes
-
     def perform
       return if Gitlab::Database.read_only?
       return unless Gitlab::Database.healthy?