Increase splay of Puma worker restarts

In order to avoid too many simultaneous regular Puma worker restarts,
increase the splay from the default of 0-5 minutes to 0-60 minutes.

Related to observations seen in https://gitlab.com/gitlab-com/gl-infra/production/-/issues/3370Signed-off-by: Ben Kochie <bjk@gitlab.com>

changelogs/unreleased/bjk-splay_puma_restarts.yml

+---
+title: Increase splay of Puma worker restarts
+merge_request: 52079
+author:
+type: other

lib/gitlab/cluster/puma_worker_killer_initializer.rb

@@ -35,6 +35,10 @@ module Gitlab
           # regularly rather than rely on OOM behavior for periodic restarting.
           config.rolling_restart_frequency = 43200 # 12 hours in seconds.
 
+          # Spread the rolling restarts out over 1 hour to avoid too many simulatneous
+          # process startups.
+          config.rolling_restart_splay_seconds = 0.0..3600.0 # 0 to 1 hour in seconds.
+
           observer = Gitlab::Cluster::PumaWorkerKillerObserver.new
           config.pre_term = observer.callback
         end