Fix leaky constant in sidekiq middleware server metrics spec

.rubocop.yml

@@ -365,7 +365,6 @@ RSpec/LeakyConstantDeclaration:
     - 'spec/lib/gitlab/no_cache_headers_spec.rb'
     - 'spec/lib/gitlab/path_regex_spec.rb'
     - 'spec/lib/gitlab/quick_actions/dsl_spec.rb'
-    - 'spec/lib/gitlab/sidekiq_middleware/server_metrics_spec.rb'
     - 'spec/lib/marginalia_spec.rb'
     - 'spec/mailers/notify_spec.rb'
     - 'spec/migrations/20191125114345_add_admin_mode_protected_path_spec.rb'

changelogs/unreleased/leaky-constant-fix-28.yml

+---
+title: Fix leaky constant issue in sidekiq middleware server metric spec
+merge_request: 32104
+author: Rajendra Kadam
+type: fixed

spec/lib/gitlab/sidekiq_middleware/server_metrics_spec.rb

@@ -164,9 +164,13 @@ describe Gitlab::SidekiqMiddleware::ServerMetrics do
     end
 
     context "when workers are not attributed" do
-      class TestNonAttributedWorker
-        include Sidekiq::Worker
+      before do
+        stub_const('TestNonAttributedWorker', Class.new)
+        TestNonAttributedWorker.class_eval do
+          include Sidekiq::Worker
+        end
       end
+
       let(:worker) { TestNonAttributedWorker.new }
       let(:labels) { default_labels.merge(urgency: "") }