Fix broken metrics_server dependencies

bin/metrics-server

 #!/usr/bin/env ruby
 # frozen_string_literal: true
 
+require_relative '../metrics_server/dependencies'
 require_relative '../metrics_server/metrics_server'
 
 target = ENV['METRICS_SERVER_TARGET']

config/initializers/7_prometheus_metrics.rb

 # frozen_string_literal: true
 
 PUMA_EXTERNAL_METRICS_SERVER = Gitlab::Utils.to_boolean(ENV['PUMA_EXTERNAL_METRICS_SERVER'])
+require Rails.root.join('metrics_server', 'metrics_server') if PUMA_EXTERNAL_METRICS_SERVER
 
 # Keep separate directories for separate processes
 def prometheus_default_multiproc_dir
@@ -74,8 +75,7 @@ Gitlab::Cluster::LifecycleEvents.on_master_start do
   if Gitlab::Runtime.puma?
     Gitlab::Metrics::Samplers::PumaSampler.instance.start
 
-    if Settings.monitoring.web_exporter.enabled && PUMA_EXTERNAL_METRICS_SERVER
-      require_relative '../../metrics_server/metrics_server'
+    if PUMA_EXTERNAL_METRICS_SERVER && Settings.monitoring.web_exporter.enabled
       MetricsServer.start_for_puma
     else
       Gitlab::Metrics::Exporter::WebExporter.instance.start

metrics_server/metrics_server.rb

@@ -2,8 +2,6 @@
 
 require_relative '../config/boot'
 
-require_relative 'dependencies'
-
 class MetricsServer # rubocop:disable Gitlab/NamespacedClass
   # The singleton instance used to supervise the Puma metrics server.
   PumaProcessSupervisor = Class.new(Gitlab::ProcessSupervisor)

sidekiq_cluster/cli.rb

@@ -10,12 +10,10 @@ require 'time'
 # we may run into "already initialized" warnings, hence the check.
 require_relative '../lib/gitlab' unless Object.const_defined?('Gitlab')
 require_relative '../lib/gitlab/utils'
-require_relative '../lib/gitlab/daemon'
 require_relative '../lib/gitlab/sidekiq_config/cli_methods'
 require_relative '../lib/gitlab/sidekiq_config/worker_matcher'
 require_relative '../lib/gitlab/sidekiq_logging/json_formatter'
-require_relative '../lib/gitlab/process_management'
-require_relative '../lib/gitlab/process_supervisor'
+require_relative '../metrics_server/dependencies'
 require_relative '../metrics_server/metrics_server'
 require_relative 'sidekiq_cluster'