Fix OpenStruct use

Fixed OpenStruct use since Ruby 3 discourages it

Changelog: changed

.rubocop_manual_todo.yml

@@ -2604,7 +2604,6 @@ Style/OpenStructUse:
     - 'spec/lib/gitlab/gitaly_client/blobs_stitcher_spec.rb'
     - 'spec/lib/gitlab/gitaly_client/diff_stitcher_spec.rb'
     - 'spec/lib/gitlab/grape_logging/loggers/exception_logger_spec.rb'
-    - 'spec/lib/gitlab/grape_logging/loggers/perf_logger_spec.rb'
     - 'spec/lib/gitlab/graphql/pagination/keyset/connection_generic_keyset_spec.rb'
     - 'spec/lib/gitlab/graphql/pagination/keyset/connection_spec.rb'
     - 'spec/lib/gitlab/legacy_github_import/project_creator_spec.rb'

spec/lib/gitlab/grape_logging/loggers/perf_logger_spec.rb

@@ -3,7 +3,7 @@
 require 'spec_helper'
 
 RSpec.describe Gitlab::GrapeLogging::Loggers::PerfLogger do
-  let(:mock_request) { OpenStruct.new(env: {}) }
+  let(:mock_request) { double('env', env: {}) }
 
   describe ".parameters" do
     subject { described_class.new.parameters(mock_request, nil) }