Fix OpenStruct use

Fixed OpenStruct use since Ruby 3 discourages it

Changelog: other

.rubocop_manual_todo.yml

@@ -2594,7 +2594,6 @@ Style/OpenStructUse:
     - 'spec/lib/gitlab/database/migrations/runner_spec.rb'
     - '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/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/exception_logger_spec.rb

@@ -3,7 +3,7 @@
 require 'spec_helper'
 
 RSpec.describe Gitlab::GrapeLogging::Loggers::ExceptionLogger do
-  let(:mock_request) { OpenStruct.new(env: {}) }
+  let(:mock_request) { double('env', env: {}) }
   let(:response_body) { nil }
 
   describe ".parameters" do
@@ -76,7 +76,7 @@ RSpec.describe Gitlab::GrapeLogging::Loggers::ExceptionLogger do
     describe 'when an exception is available' do
       let(:exception) { RuntimeError.new('This is a test') }
       let(:mock_request) do
-        OpenStruct.new(
+        double('env',
           env: {
             ::API::Helpers::API_EXCEPTION_ENV => exception
           }