Fix OpenStruct use

Fixes OpenStruct in accept_spec since Ruby 3 discourages it

Changelog: changed

.rubocop_manual_todo.yml

@@ -2561,7 +2561,6 @@ Style/OpenStructUse:
     - 'ee/spec/features/projects/new_project_spec.rb'
     - 'ee/spec/finders/template_finder_spec.rb'
     - 'ee/spec/graphql/ee/resolvers/board_lists_resolver_spec.rb'
-    - 'ee/spec/graphql/mutations/merge_requests/accept_spec.rb'
     - 'ee/spec/graphql/resolvers/board_groupings/epics_resolvers_spec.rb'
     - 'ee/spec/helpers/billing_plans_helper_spec.rb'
     - 'ee/spec/helpers/ee/blob_helper_spec.rb'

ee/spec/graphql/mutations/merge_requests/accept_spec.rb

@@ -4,13 +4,14 @@ require 'spec_helper'
 
 RSpec.describe Mutations::MergeRequests::Accept do
   let_it_be(:user) { create(:user) }
+
   let(:project) { create(:project, :public, :repository) }
 
   subject(:mutation) { described_class.new(context: context, object: nil, field: nil) }
 
-  let_it_be(:context) do
+  let(:context) do
     GraphQL::Query::Context.new(
-      query: OpenStruct.new(schema: GitlabSchema),
+      query: double('query', schema: GitlabSchema),
       values: { current_user: user },
       object: nil
     )