Enable builds queue on replicas by default

This removes the ci_runner_builds_queue_on_replicas
feature flag, enabling runner builds for all instances
by default

Changelog: changed

config/feature_flags/development/ci_runner_builds_queue_on_replicas.yml

----
-name: ci_runner_builds_queue_on_replicas
-introduced_by_url: https://gitlab.com/gitlab-org/gitlab/-/merge_requests/56849
-rollout_issue_url: https://gitlab.com/gitlab-org/gitlab/-/issues/325723
-milestone: '13.10'
-type: development
-group: group::continuous integration
-default_enabled: true

ee/app/models/ee/ci/runner.rb

@@ -18,8 +18,6 @@ module EE
       end
 
       def heartbeat(values)
-        return super unless ::Feature.enabled?(:ci_runner_builds_queue_on_replicas, self, default_enabled: :yaml)
-
         ##
         # We can safely ignore writes performed by a runner heartbeat. We do
         # not want to upgrade database connection proxy to use the primary

ee/app/services/ee/ci/register_job_service.rb

@@ -29,13 +29,11 @@ module EE
       end
 
       def retrieve_queue(queue_query_proc)
-        if ::Feature.enabled?(:ci_runner_builds_queue_on_replicas, runner, default_enabled: :yaml)
-          ##
-          # We want to reset a load balancing session to discard the side
-          # effects of writes that could have happened prior to this moment.
-          #
-          ::Gitlab::Database::LoadBalancing::Session.clear_session
-        end
+        ##
+        # We want to reset a load balancing session to discard the side
+        # effects of writes that could have happened prior to this moment.
+        #
+        ::Gitlab::Database::LoadBalancing::Session.clear_session
 
         super
       end