Merge branch '43424-put_all_event_metrics_behind_feature_flags' into 'master'

Fix for sidekiq metrics set cardinality growing unbounded

Closes #43424

See merge request gitlab-org/gitlab-ce!17235

lib/gitlab/metrics/transaction.rb

@@ -73,7 +73,7 @@ module Gitlab
       # event_name - The name of the event (e.g. "git_push").
       # tags - A set of tags to attach to the event.
       def add_event(event_name, tags = {})
-        self.class.transaction_metric(event_name, :counter, prefix: 'event_', tags: tags).increment(tags.merge(labels))
+        self.class.transaction_metric(event_name, :counter, prefix: 'event_', use_feature_flag: true, tags: tags).increment(tags.merge(labels))
         @metrics << Metric.new(EVENT_SERIES, { count: 1 }, tags.merge(event: event_name), :event)
       end
 
@@ -150,11 +150,12 @@ module Gitlab
         with_feature :prometheus_metrics_transaction_allocated_memory
       end
 
-      def self.transaction_metric(name, type, prefix: nil, tags: {})
+      def self.transaction_metric(name, type, prefix: nil, use_feature_flag: false, tags: {})
         metric_name = "gitlab_transaction_#{prefix}#{name}_total".to_sym
         fetch_metric(type, metric_name) do
           docstring "Transaction #{prefix}#{name} #{type}"
           base_labels tags.merge(BASE_LABELS)
+          with_feature "prometheus_transaction_#{prefix}#{name}_total".to_sym if use_feature_flag
 
           if type == :gauge
             multiprocess_mode :livesum